I had a great tour through the swiss alps on the weekend with my 100M which had a full engine rebuilt 9000mls ago (but: this was in the 80s..... the car was sitting in a collection then for a long period afterwards). the tour was a great experience we have passed a lot of scenic routes and towns like st.moritz, klosters or davos..... the car performed well; perfect oil pressure, perfect water and oil temperature, perfect alfin drum brakes. it was a sheer pleasure....

but:

the car needed lotīs of oil (around 2 litres for 1000kms) but there is no blue smoke, only the normal leaks (which we all know) and also no other bad signs (no oil in the water etc.).

Now I donīt know what to think about this??? It never consumed so much before and I had a new oil service (20W50) before starting to switzerland.

Do you have any ideas how to proceed now???

Thank you for your recommendations!!

Wolfgang

Hello Wolfgang,

I did not have special experience in 100 M engines. But I have some ideas which way the oil can gone...the way over the valve stem seals( only an o-ring) and over the piston oil seal rings. Do you know your oil specification is really 20-w50 ? (mineralisch)
But I hope for you , the crank case ventilation is the reason of your challenge. Check the way from the valve cover to the area of the sucking access. Is the way completly open or closed and you have some missing deflector sheets or metal spongs?
Or a new AL-valve cover with no deflector...
If there is all ok ,I would change first the stem seals....
Did you check your compression parameters, with and without oil filling in the spark plug holes ? This is only to get a feeling for your cylinder condition.

I hope the best.


Yours Michel- who lives near Frankfurt

I'm not familiar w that particular engine...

BUT I'd be looking for excessive venting of oil, OR leaking past valve stem seals or piston rings. MIGHT be just enough of a leak to consume oil, but not enough for you to notice blue smoke.

2 Liters does seem like a lot of oil... What does the bottom of the car look like? Any signs of oil being sprayed on the underside?

I had a Jag E-type once where the previous owner had reversed the crankcase ventilation hoses. Blew oil EVERYWHERE!! Got so bad that I could barely see cars behind me!! This was on a cross-country trip right after purchase.... After MANY stops and refills we finally gave in and put the car on a trailer for the remainder of the trip. This saved the engine, but blew the initial purchase/transportation budget. "Oh Well!"

I had a Ford F-250 Pick-up once that drank about a quart of oil w every fill-up of gas. Never saw any smoke, but oil kept "disappearing". Turned out to be bad valve stem seals.

As mentioned above, check the compression, check the crankcase ventilation.

Good Luck!
-Bear-

One of the most common causes of this problem is worn rocker arm bushings.

With the cover removed & the engine idling, there should be no more than a drip about every two seconds from any individual rocker arm. These engines do not tolerate excessive oil flow down the valve guides/stems.

A steady stream, or heaven forbid, an oil gusher would indicate the need to rebuild the rocker arm/bushing assembly. Not as easy as it would first appear. Some replacement bushings do not have their slots in the correct places & can make the problem worse.
D

Thank you for all your recommendations. I have checked the compression yesterday evening and the instrument has shown between 11,5 and 12,5 bar at the single cylinders which - in my opinion - is more than adequate. So I do not have worn cylinders as it seems.

I will check Daveīs recommendation concerning the rocker arms this evening and will report again.

The only thing I did not understand well is how to check out the crankcase ventilation. Could anybody explain how to proceed there???

Thank you again, Wolfgang

The crankcase ventilation consists of a road draft tube exiting the side cover on the left side & a baffled vent from the tappet cover to the air intake.
D

Wolfgang, just a thought, on the oil change recently, do you know who did it?

Did they know that these cars take lke twice as much oil as most modern cars? maybe it wasn't filled properly in the first place.

Two liters is a lot of oil, it is hard to lose that much without a visible sign, also my motor seemed to have some blowby--oil leak issues until the rings were fully seated after and engine rebuild, maybe a blowby/crankcase pressure issue.

Hi Dave,
thank you for your explanation. I already found the tube on the left side cover. I can take it off and check whether there is any dirt in it.
I am so sorry but I cannot understand the second thing (baffled vent...). Can I see this thing on any drawing in a catalogue or so????
Sorry again for my bad english and thank you so much for your help!!!
Wolfgang

Dave's reference to the baffled vent is I believe is the one in the valve cover I believe, this should be a little metal extension coming out of your valve cover which will have a rubber hose attached to it going to the carburators--it is baffled on the inside of the valve cover.

If you have an aftermarket valve cover you may or may not have the vent.

Hi Glemon, thank you for your explanation. Now I know what is meant. The metal extension ist there and there is also a rubber hose to the col air box. My valve cover is aftermarket and it is not baffled on the inside; I hope that this is no problem. Sorry again for taking part in the forum with a bad technical english like mine....

Dave, I have checked the oil-flow coming from the rocker arms. I think that you are completely right: This seems to be the problem. There is a slow but steady flow form every rocker arm at idling revs. The flow looks very equal on every rocker arm. I am not so clear about the problem which results from this.... I assume that the oil flow is too much at normal driving revs and the oil is looking for a way out as the normal way through the valve guides/stems is not sufficient for the capacity which has to pass. Right? But what happens then? Does the oil come out through the crankcase ventilation or what happens next??

Hello,

I guess it is possible that the simple sealing construction did not seal really the oil flow from the top. See the picture http://en.wikipedia.org/wiki/Rocker_arm
See also position 50 http://www.limora.com/index/lang-1/lkz-1...oesserungtop=30

Yours michel- by the way, your english is better than mine (a german healey forum does not exist, but you have here the compent experience of the whole healey world)

Dave,

another thing: Would it maybe be possible that my engine has too much oil pressure?? Can this lead to the steady flow coming out from the rocker arms?? As I have learned the oil pressure at the 100 engine should be around 50psi at 3000revs; mine is between 60psi and 70psi when warm. If this could be the problem: Are there any adjusting possibilities to bring back the oil pressure to a normal level??

Thank you again, Wolfgang

The basic problem is that the oil must drain back down to the sump via the very limited areas round the pushrod clearance holes in the cylinder head. The normal way. Excessive oil tends to flood the valve stems if it can't drain down fast enough. The simple o ring valve stem seals cannot withstand much excess oil flow.

Higher than normal oil pressure, I would say 60 psi maximum, could increase the problem somewhat but would not be the sole problem. This pressure is somemhat adjustable by changing the relief valve tension.

Someone asked earlier, SAE 20-W 50 oil is used by many Healey folks.
D

Dave,
thank you for your answer. So the next step will be to lower the tension of the relief valve a little bit and see what happens to the oil flow on the rockers. If this will not cure the problem - which is obviously very likely - I will have to put in new bushings. I will report again as solving the problem could maybe also be interesting for other members.

What I am also wondering about is that there is no blue smoke from the exhaust if the problem is that the o ring seals cannot withstand the oil flow? According to my understanding there should be blue smoke in the is case. Right?

I don't know how you could be losing that much oil from excessive valvtrain seepage wirhout seeing either blue smoke (may no appear or get too bad until the car is pretty warm) or seeing it leaking down the block somewhere.

I think you need to recheck your observations/assumptions.

If the engine really is using that much oil, it has to be going somewhere.

Into the combustion chambers & out as blue smoke

Into the cooling system

Leaking out various locations to the ground

Someone is playing jokes on you

It cannot just evaporate into thin air
D

Your engine unknown to me but changing the rocket gear on my '63 BJ7 made an incredible improvement to both oil consumption and overall pressure (10/15 psi). Mine, prior to change, resembled a row of mini waterfalls : the 'new'' one ( I installed a reconditioned) bothered me on initial startup because there were only dribbles apparent --- I wondered if the was any oil there at first!!

I agree with Dave, maybe the best step at this time is to make sure oil is topped up, wipe any evidence of leakage/seapage you can get to off the motor, and monitor oil use, leakage, or any other evidence of use such as blue smoke.

These engines have relatively huge sumps and you have to lose a lot of oil before you run into any sort of oil supply/lubrication problems, so as long as you are monitoring it you should be OK.

Dave, John, Glemon,
thank you for your comments. Itīs so helpful especially for a technical novice concerning the 100 engine like me. Based on this I will do the cleaning job on the weekend, top up the oil and do a longer drive to see where oil is coming out. I will report again....
I wish all of you a very nice weekend!

I occasionally use a "black light" oil tracer system to pinpoint hard to find leaks. These tracer systems are readily available from many auto supply stores & vary from quite cheap to more elaborate.

All external leaked oil should be as throughly removed as possible. Very important.

A small quantity of chemical would be introduced into the engine crankcase oil.

A typical low cost system would use a 12 volt, 50 watt detector light in conjunction with contrast enhancing glasses. It probably still should be viewed under low ambient light conditions to get maximum contrast.

It's surprising how many times the leak is originating from a completely different location than you might imagine. It is frequently only necessary to only run the engine on jack stands to spot the leak origin. If you drive the car, it's likely to just spread the leak around & make the source less distinct.

The same method can be used to spot leaks of the transmission oil.
D

Just a short report how things are going on concerning my oil problem:

I have connected the tube exiting the side cover with a small bottle to see whether oil is coming out here -> result after 200kms: nearly zero oil in the bottle; just a few drops

Next check: I have connected the baffled vent from the tappet cover with a small bottle, too. -> result: the same, just a few oil drops on the bottom of the bottle

Next thing will be to check whether the tappet cover and the oil sump are sealed perfectly.....

I will report again.

I am starting to run out of ideas.....

I have checked the sump now and have refitted it properly -> no oil leak from this side. I have also removed the oil-pipe near the rear seal which leads into the sump as recommended.

I have mounted a new speedo cable which was the reason for some oil dropping down as the outer cable was damaged -> no oil leaks from this side anymore.

I have checked the tappet cover which seems to be properly mounted as there is no oil coming out.

The containers (fitted by myself) connected with the vents from the valve cover and the side tappet cover does not show any signs of oil in them (only some small amount of oil steam...).

When the engine is running, there does not seem to be any oil dropping at idle speed. When the engine is turned of some drops are exiting from the normal position between engine and gearbox.

There is still no blue smoke from the exhaust and the spark plugs are very light brown (which does not seem bad; maybe the carbs have to be adjusted a little bit more rich..).

But:::::: The oil consumption ist still astronomic: It went down from max to min at the dipstick in only 150mls......

Next thing I will do is to let the engine run at 3000revs for some minutes and check underneath whether I can detect any leaks then....

Do you have other ideas how to proceed?

Thank you very much for your support!!! Wolfgang

Wolfgang -

I am sorry to report to you that Dave Russell is very ill with cancer and is not posting any more to this list. Let's give him our very best prayers, he is very sick - it came on very suddenly.

With respect to your problem, I would have to agree with Dave. I do suspect it is leaking from the rockers into the valves and burning off, even if you don't see the blue smoke.

As long as your spark plugs aren't getting fouled with oil, it's generally ok to drive the car with it burning a little oil. When it starts getting too much, you'll need to take your rocker off and have it rebuilt.

One very important thing - when you remove your rocker, DO NOT remove (and later install) the banjo bolt first. It is better to undo the oil feed pipe at the point where it connects to the cylinder head and then remove the banjo bolt afterward (and more important when installing, install the banjo bolt and oil feed tube to the rocker FIRST, slightly loose, then install the rocker on the head, then finally attach and tighten the oil feed tube to the head). If you don't do things in this order you will strip out the rocker shaft pedestal's oil feed tube attachment threads. Maybe to clarify - when removing the rocker -> the banjo bolt comes out last, when installing the rocker -> the banjo bolt goes on the rocker first before installation.

Good Luck!

Alan -

thank you very much again...

I am very sad to hear about Daveīs health; I hope that there is a good chance for him to get better again. Let us all hope the best for him!

As I am not an engine-specialist I can only follow your recommendation. I am only surprised that such a volume of burned oil cannot be detected or smelled at the exhaust...

I assume that the work can be done without removing the head, right?

I will check for a suitable specialist in southern germany as I have learned from other threads that it is not an easy diy job...

All the best, Wolfgang

Wolfgang, I still go back to Dave's comments on oil consumption, a quart of oil or whatever it takes to make the dipstick go from max to min looks like a lot of oil on the floor of your garage or when going up in blue smoke, I had a Tiumph with a very wron motor that smoked in huge obnoxious quantities but I could drive about 300 400 miles before adding a quart, light brown is good for the plugs, if burning a lot they should be more black and sooty looking.

As far as checking the oil, have you tried letting the engine sit for a while before checking, as sometimes more oil settles back into the pan after it sits.

Also is your initial check when full right after an oil change? maybe the filter hasn't filled yet and this makes it go down.

Oil is relatively cheap and the fixes can be expensive, as long as you are keeping things monitored and topped up you can keep driving and monitoring for a while to try to figure it out.

The rear main crank seal would probably empty out into the tranny bell housing, but that oil would have to come out eventually too.

I do like Dave's idea about the black light test, I think he explained it pretty well, but you basically add a little additive to the oil and then using a special light it really stands out or glows as it comes out of the motor.

Do you have access to a lift? being able to stand under the car and check things out can really help as opposed to crawling around on your back and looking.

glemon -

thank you very much for your comments. I already did the black light test and detected an oil loss coming from the speedo (revs) cable (there were quite a lot of drops as long as the engine was running) and I have already fixed this leak. But this was not not the reason for the heavy consumption unfortunately

I was checking the oil level at the dipstick when the engine was cold and the car sitting for a few hours because I also thought that the level should be checked always at the same conditions.

The rear main crank seal is a problem on my car but the volume of drops which eventually come out after stopping the engine is very limited. And - in my opinion - this is normal for the 100 engine.

I have noticed the oil consumption problem for the first time after changing the oil and re-checking the level after a long run. During the oil change I have also changed the oil filter to the modern type (sorry but I do not remember the specifica name for this modern filter version). But I suspect that the oil and filter change can be the reason as I did this shortly after buying the car and I donīt know anything about itīs consumption before.

But coming back to Daveīs advise: Either the oil is burned in the engine or it has to come out somewhere! So what I will do is to let the engine rev at 3000 or so when the car stands still for some minutes and checke whether any significant leaking starts.... I do not haveīother ideas.... And if this is not the case (no leaks) I will measure the "data" of the exhaust smoke because - in my opinion - they should be cruel if so much oil is burned, right?? In this case the next step obviously would be to make the rocker assembly repair.....

Wolfgang--

If you do not have a rear seal kit installed or if your rear seal is worn your engine will likely blow more oil out if the oil level is at the "full" mark, and will blow less as it approaches the "fill" mark. Why not let your oil come down to the lower level and see if consumption drops off a bit.

An additional thought--perhaps your dipstick is miscalibrated or is not seating all the way down causing you to overfill the sump. I believe 7 US quarts should fill engine and filter--how much does your car require?

Friends:

I've read this thread for some time. My Healey has had major oil leaks but usually consumed less than a qt every 400 miles or so.

I had another old car that consumed oil like Wolfgangs, it burned a quart every 150 miles or more. And guess what, almost no smoke at all from this car.

However, when I followed the car I could clearly smell burning oil even though there was little visible smoke.

I eventually learned that engine had many broken rings and ring lands. When I put new pistons and rings in that car, the oil consumption dropped to practically nothing.

I suggest that Wolfgang's car is burning the oil, probably due to bad rings or pistons. Since his leaks are under control, there really is no other credible explanation. Oil is either getting into the cylinders via the rings or through valve guides. The only way to find out for sure is to pull the pistons and look, measure, and renew. And replace the valve seals and rework and magnaflux the head while you are at it. I think if you do this you will cut your oil consumption drastically.

Good luck!

Don't forget about the differential compression test. Any piston engine aircraft shop will have a tester, and you can buy them for from 50 to 150 dollars. You put each cylinder, in turn, at TDC and with the engine warm, put about 80 psi into one cylinder at a time with a spark plug adapter. With the piston at TDC on compression, if there is ring blow by you will hear air hissing our the case vent. If there is valve blow by you will hear it out the intake (carbs) or our the exhaust pipe. The aircraft testers have a calibrated orifice between two pressure gages that allow you to see the amount of leakdown from a fixed input pressure. If you put in 80 psi and can't hold 60 in the cylinder most aircraft people will change a cylinder. It you buy it through an automotive store I'm sure it would come with directions. Really any goo auto shop should have one too.

Michael, healey 100, Jon,

thank you very much for your help and your recommendations. I will have a lot to do during the weekend now..... I am happy to do all things I can manage on my own first. I will need professional help to put off the head and check the pistons. So I will start to check how much oil is transported to the rocker section when the engine is reving higher than idle speed. Dave suggested me to do so earlier but I have only checked this at idle speed yet (my mistake). Maybe I can check this through the oil filler cap in the valve cover?? Dave and others have told me that too much oil in the rocker section could cause my problem. I think that itīs advisable to check this before putting the head of, right?

Wolfgang

Roscoe, no need to have to go to an aircraft shop.

In automotive land this test is called a cylinder leakage test(cylinder leakdown test).

Testers can be found at just about any well equipped auto parts store or tool truck. Or can even be made relatively inexpensively. I consider it a very good test, helping to pinpoint combustion loss.

Wolfgang:

It is always best to do all the testing you can before pulling the head and pistons, this is a big job. So keep looking for leaks and external causes.

If the oil is not returning to the sump from the rockers, you either have a badly leaking rocker oiling system (this should be visible when running the engine with the rocker cover off) or your crankcase pressure is so high that oil cannot return by gravity to the sump. If the latter is the problem, you will need to renew rings, pistons, and/or bores to fix it.

Good luck
Bill

A leakdown tester will allow you to test the efficiency of each cylinder and might point the way to the source of the oil leak. By removing the rocker arm so that your valves stay closed you can test each cylinder for the condition of the valves as well as the ring seal at various heights in the bore simply by rolling over the engine and testing from TDC to BDC, etc. For example a cylinder wall might be scratched at the bottom and the leak would show as the piston is lowered and tested at say, top, middle and bottom of stroke.

BTW this may be obvious but I always bring the first guage to 100 psi and then crack the valve and read the second guage as a simple percentage. Naturally you want as close to 100% as possible and 90% to 95% is about minimum for a street engine.

Ba da bing, I am going to make my guess, because I experienced it on my Healey motor before the rebuild, but maybe not as badly, you are getting blowby from worn rings and bores, which is of course greater at greater RPM, this blows oil out the rear main scroll seal as you go down the road--but not so much leaking at idle or sitting with the engine off.

Anyway as stated by the others a leakdown test, or evne the simpler compression test should tell you something about the sealing capability of your rings and valves.

Bad news is if I am right the motor will need a rebuild eventually...please do note that Road and Track did right about these cars that the motors were low stressed rbust units that tended to increase their tolerences and burn more oil as they wore out, but would go and go even in that state, I drove my 100 for many years with low compression before the rebuild.

Hi there,

just to keep you updated: My next step is to put off the rocker assembly and send the complete unit to Steve at ukhealey.co.uk.

He is offering a complete rebuilt of the assembly at a very reasonable rate and - as I have noticed - it does not seem to be an easy DIY-job, right?

I will come back to you as soon as there are news concerning my problem.....

Best wishes from sunny Bavaria, Wolfgang