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TR4/4A Engine--I'm Worried

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KVH

KVH

Obi Wan
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I'm very worried about my engine. I rebuilt it about six months ago. After starting up the last two times there is a noticeable "chirp" sound coming from the block. The sound appears to be coming from the area of the fuel pump but also possibly as high as the valve cover.

When I say chirp, it's a bit of a knock, but a high-pitched chirp/knock. It disappears as soon as the engine starts to reach operating temperature.

It runs perfectly with no knock whatsoever once it reaches operating temperature. Do I have a blown bearing a bad camshaft? What's going on here?
 
I feel like an aging bumbler. After all I've been through over the years, you would think I would check my oil more frequently. However, I've not expected such a rapid loss of oil. About three weeks ago I was down a half a quart. After hearing this knocking sound, I checked my oil level. My oil was down a little over 2 full quarts. I assume that was my problem, and now my questions are whether I've done any serious damage to the engine, and what it is that could possibly be making me consume all oil that rapidly. Thanks for any thoughts or welcome insults.
 
So the noise went away after adding oil?

Lots of places for oil to leak, you'll need to do some detective work. How badly does it "mark it's spot" ? Does it blow blue smoke under some conditions? What are the conditions?

Marking it's spot indicates a leak directly from the engine, so you'll need to track where the leak is. Common places (not in order) include the rear main seal (especially if you are running the stock PCV system and the rings are not sealing perfectly), rocker cover gasket, front main seal, oil pan gasket, push rod tubes, fuel pump gasket, generator mounting bolts, and coil mounting bolts. (The generator and coil bolts go all the way through the outer wall of the block, so if one fell out you'll get a major oil leak.) Less common but still possible are the cam bearing locating bolts, the plug behind the camshaft bore, and the screwed plug in the back of the cylinder head. Oh yeah, don't forget the oil filter head itself, which has multiple places that might leak. A common problem here is that someone failed to remove the old canister sealing ring when doing an oil change. Oddly enough, having two rings installed almost guarantees a leak.

If the exhaust is blue primarily under heavy throttle, then oil is getting past the rings and cylinder walls. If it's blue primarily when backing off the throttle (eg shifting gears), then oil is getting past the intake valve guides.

As far as further damage from running low on oil, my approach would be to continue to drive it and see what other symptoms develop. Chances are that there is some damage or accelerated wear from lack of lubrication. But if the part was destroyed, you would already know it by now. So you may have only shaved (for example), 10,000 miles off of a 150,000 mile lifetime (meaning you'll rebuild the engine for other reasons before the rapid wear on this part becomes an issue).
 
So many possibilities here. Ring gap, bearing clearances, gaskets, seals and etc. If the shop was not proficient in Triumphs, could be the source. But, engine is not broke in yet. Did you do a ring set with break-in oil for 20 mins. at 2000 rpm. Some say not necessary, but does help. Retorque head gasket at 500 miles and again at 1000 miles. Had this problem on a friends Jag, shop unfamiliar with engine, and I rebuilt it at 500 miles. Leaked oil everywhere, cost him a mint and as a favor used $700 in parts and 2 months time to redo. Runs excellent, found a couple small leaks, upgraded seals to new apps and still going strong. Check engine close and hope the tolerances were adhered to. Continue to check oil, if it does not improve, it will have to come apart and checked.
 
Thanks all. It took 2.3 quarts to reach the "full" line. I never noticed any leaks of any significance on the floor. I put in a new rear main seal, the one everyone recommends here (vitron?). I'm the engine rebuilder. This is my third rebuild. I followed all the break in rules, and used Zinc, etc. I was careful with those rings. I must be burning oil. I had a shop redo the head and valves for me. I do recall once seeing a blue cloud but only on start up.
 
That chirp could be from a valve...either dry or just too tight in the valve guide.
 
KVH said:
Thanks all. It took 2.3 quarts to reach the "full" line...
Click to expand...

I doubt that would cause a problem. As I recall it is 2 quarts from 'add' to 'full' so you were really only 0.3 quarts below minimum acceptable. Surely that would be enough to keep the oil pump pick-up submerged?
 
I can only add what I found on a "Expert" engine build. The packing at the top of the distributor had not been done and the end float was not there and caused a little knock or chirp. Took forever to find it as all indications were in the valve train.

Wayne
 
TR3driver said:
Does it blow blue smoke under some conditions? What are the conditions? If the exhaust is blue primarily under heavy throttle, then oil is getting past the rings and cylinder walls. If it's blue primarily when backing off the throttle (eg shifting gears), then oil is getting past the intake valve guides.
Click to expand...

I had two folks watch as I accelerated and shifted, bringing RPMs up to about 4500. I also punched the accelerator from idle.

Each time, the exhaust was sending black clouds, not blue.

I drove 60 miles today in the worst of the heat. I appear to have lost about 1/8th of a quart.

Is this valves? Rings? Carb mixture adjustments?

I was really careful on the rebuild, but I'm now wishing I'd used Grant Rings instead of the ones that came with the pistons. The valves are new from Moss and installed by the guys who worked on the head. The head guy at the shop has 45 years of experience so I'm not inclined to suspect any poor work. They did work on the valve seats and guides.

As best I can tell, the problem is at pistons 3 and 4. I say that because those are the plugs most fouled with black soot. If it's oil blow-by, wouldn't I see the plugs "wet"?

Does anyone think that if I remove my PCV valve that might help? I ask because I also have an engine vent tube and the PCV valve shouldn't be necessary.

The car otherwise runs great.

Thanks for any further thoughts guys.
 
Black clouds? By that I assume you mean a lot, not just wisps or a little visible vapor from the tailpipe. If so that definitely doesn't sound right. I would do a compression check just to get some idea of the state of the motor and then double check timing and ignition as well as checking for sticky choke linkage.

The lower oil level should not have hurt anything. Always keep an eye on your oil gauge, especially now. I had an old Sprite years ago as a daily driver, I would add oil when I saw the pressure guage start to fluctuate, indicating oil starvation at the pump. Not the best way to do it, but the big four has a big oil pan and large oil capacity, two quarts down probably didn't create any issues.

As for the chirp, could be just about anything, I have often been way off about where a sound is coming from by listening. Eliminate external sources before you tear into the motor.
 
Lots of black smoke means way too rich. Way too rich can scrub the cylinder walls and drastically thin out the oil causing accelerated wear and high consumption. Check your oil. Does it seem too thin? Does it smell like gas? x
 
If the vent tube is open to the sump, the pcv does nothing.
As for the plugs, they might not be oily if the cylinders still fire. (You might try a swab in the plug hole with the piston near to top to check for oil).
A 60 mile run is not enough, in my opinion, to check oil consumption. I'd run it a few miles a day for a week or two. I'd also look closely, as Randall suggested earlier, for a leak. Clean cardboard, poster board, or a perfectly clean garage floor will help. Try running the engine over the cardboard, if you haven't done that already. If it is losing as much as you suspect, the leak will be obvious.
However, the smoke is another issue. The black smoke you see could be unrelated to the oil loss or it could indicate an internal engine issue. While oil smoke is invariably blue, adding a bit of rich mixture to the oil could produce the black. (you should be able to smell the gas in the smoke).
While driving, take a spin or two with an eye in the rear view or someone following you to check the smoke. Again, if you are losing as much as you think, the smoke will be quite noticeable.
Finally, make sure there's no oil in the coolant and vice versa.
Tom
 
The oil does smell a bit like gas, but I'm not sure more than usual. Thickness seems OK, maybe a bit thinner than 20/50 I run. I leaned up the carbs and it runs great, but still a little black smoke on shifting. Could any of this be my Pertronix Distributor. I've never like it.
 
Not likely to be the distributor, somehow the engine is getting too much fuel. I'd solve that first, then revisit the oil loss issue.

Purely as a side comment, the early TR3 owner's manual states that when oil consumption exceeds 1 gallon per 1000 miles, it "will be desirable" to use the next heavier grade of oil :smile:

BTW, having the vent tube plus PCV valve is going to leak air into the intake manifold. That might even be how your oil is getting into the cylinders. I would disconnect and plug the PCV line, at least as an experiment to see what effect it has.
 
TR3driver said:
". . . somehow the engine is getting too much fuel. . . . BTW, having the vent tube plus PCV valve is going to leak air into the intake manifold. That might even be how your oil is getting into the cylinders. I would disconnect and plug the PCV line, at least as an experiment to see what effect it has.
Click to expand...

OK, I'll try plugging the Valve cover outlet, too. A lot of air blows out that outlet vent, however, and I wonder where that air can go--if not back down into the lower engine.

When the manual says to verify a 1/8" gap between the bowl lid and the float, do they mean as it just rests upside down, or do they mean after you push down on the tiny spring loaded valve needle? It makes a huge difference.

Also, I'm beginning to think that my jet assembly might be bad. Do the jets widen and allow too much fuel over time? When must jets be replaced?

As another experiment, maybe grasping at straws, I just replaced my Viton tipped needle in the forward carb with a steel tipped grose jet type.
 
The air is coming from the lower engine, so it should just go out the vent tube. BTW, that "air" is compression gases going past the rings.

The jet can definitely wear on SU carbs; how quickly depends on how well centered the needle is (was). I don't know about ZS carbs, but suspect they suffer from the same disease. In fact, I believe that wear in the jet is one of the primary reasons that so many TR3s tend to overheat. The wear causes the mixture to go rich at idle; and people lean out the mixture to get it right at idle. Then the extremely lean mixture at cruise causes poor combustion and overheating. On my Dad's TR3A (the first one I was responsible for maintaining), the exhaust manifold would literally glow red.

It appears that the spring gets fully compressed before the valve will hold back fuel pressure, so I've always assumed that the float level should be set with the spring compressed. BTW, I don't have the book handy, but 1/8" sounds really small. It's much larger (like 7/16") on the earlier carbs.
 
I do remember the 7/16 rod for adjustment of the float arm with the assembly upside down. If the arm is bent at a 1/8 upside down, that could explain a lot. Like high carbon build up and washing oil away in the cylinder chamber causing high oil consumption and none seating rings. The oil would be very dark and smell like fuel. On a new motor this would/could be harmful because the friction is higher in a new motor, plus perhaps, causing something to squeak from lack of lubrication from washing the oil out with fuel.
 
I too have that chirping at startup and goes away for the most part when warm. I went out and checked my oil and it's down a 1/4" but I been plagued with a leaky valve cover too. This is in my TR3 so there is no PCV valve and if KVH is running a Pertronix Distributor then that would eliminate that and probably mine too. I didn't know there was packing in a distributor or where it is even located. So I'm more worried about the valves. That was my first concern as my TR250 starting making a similar noise and found a broken valve spring.
Could I test to see if the guides are tight by squirting some thin oil into the valve springs and then start the engine and listen for the sound?
 
Got_All_4 said:
I too have that chirping at startup and goes away for the most part when warm. I went out and checked my oil and it's down a 1/4" but I been plagued with a leaky valve cover too. This is in my TR3 so there is no PCV valve and if KVH is running a Pertronix Distributor then that would eliminate that and probably mine too. I didn't know there was packing in a distributor or where it is even located. So I'm more worried about the valves. That was my first concern as my TR250 starting making a similar noise and found a broken valve spring.
Could I test to see if the guides are tight by squirting some thin oil into the valve springs and then start the engine and listen for the sound?
Click to expand...

My problem is nearly solved/repaired. As set out in my other posts, I made a slight, little, tiny, somewhat irrelevant, moderately insignificant, and totally understandable error on my engine rebuild. I ignored the instructions and installed my scraper rings wrong! I was fire-hosing my oil out the tailpipe not even realizing how low my oil was getting--hence the engine knock. You know--no oil. I'm not letting that bother me, though. I'm over it now. Uh, huh. Totally.

On yours, that sounds odd to me. Are you sure it's not a generator or alternator bearing, or a fan belt that should be soaped up? I might suspect valve lifters, but don't know that a valve, itself, or even a spring would do that, but you can sure check those springs easily by popping the valve cover.
 
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