Engine Flush After Head Gasket Leak

[AUSMHLY]

My head gasket leaked, with just 500 miles on the rebuilt engine. Showed between block and cylinder head and top of cylinder. I'm replacing the head gasket.

"Driven" brand break-in oil looked OK on the dip stick and black when drained, not milky. I'll assume there will still be some oil/antifreeze in the block after draining. As careful as I tried to be when cleaning the head, some debris may have gotten in the oil/antifreeze holes; concerned. The radiator flush should take care of the water side. I'd like to flush the oil. What's the safest best way do that?

There are oil-flush additives, but I'm concerned they may damage the bearings.

Maybe use conventional inexpensive 20/50 oil and Fram Ultra Synthetic XG3600 filter (filters to 20 microns), idle 5 minutes (shorter or longer?) and drain? Repeat, new oil/filter, idle, drain? Third time use conventional Valvoline VR1 racing oil and new Fram XG3600 filter?

Inexpensive oil will not have a high level of zinc, if any.

Still concerned about the bearings.

I'm using it as a flush.

Cheap oil or Valvoline VR1?

I look forward to your thoughts and suggestions.

Cheers

 

[BigGreen]

Additives for flushing are for the dirt from using the engine for serious periods.
Yours is as new after 500 miles, just give the oil time (over night) to leak.

I would not run an almost new engine with transmission oil.

Any oil that comes in contact with water / coolant will look like mayonaise (emulsion, see your picture)
That should be visible (in the oil) at the first drain. Repeat as much as you like until you feel good.
You can save the used oil for later flushing jobs.

For debris, one never knows how fast it will reach the filter or the sump.

 

[LarryK]

I use transmission fluid. Fill drop and refill. Run 500 miles drop and put in good oil, changing fuel filter to get mush out.

 

[AUSMHLY]

Additives for flushing are for the dirt from using the engine for serious periods.
Yours is as new after 500 miles, just give the oil time (over night) to leak.

I would not run an almost new engine with transmission oil.

Any oil that comes in contact with water / coolant will look like mayonaise (emulsion, see your picture)
That should be visible (in the oil) at the first drain. Repeat as much as you like until you feel good.
You can save the used oil for later flushing jobs.

For debris, one never knows how fast it will reach the filter or the sump.

Thanks BigGreen,

"Just give the oil time (over night) to leak."
Jacked up the front so the oil will collect at the drain plug. Drained overnight to get as much oil out as possible without removing the oil pan.

Happy to say the oil I drained was black and not mayonnaise looking. Only noticed that on the cylinder head, which is interesting.

"Repeat as much as you like until you feel good."
1) Would 2 oil changes be enough?

2) How long should I let the car idle with new oil before draining?
I don't want to run too long in case there is debris/antifreeze mixing with the new oil creating damage before the filter can capture all of it. But long enough for the filter to catch what it can. Hence draining the contaminated oil and start over with new oil.

3) "You can save the used oil for later flushing jobs."
I'm not following you. Isn't the used oil contaminated with antifreeze and debris?

4) How important is it to use a high zinc oil for this flushing process?
Can I use conventional 20W-50 without high zinc for what ever time I should Idle?
Walmart Supertech 20W-50 oil is made by Warren Oil Company, who makes oil for a lot of no brands like Amazonbasics. Reviews say it's good oil that meets all the specs.
Supertech low zinc 5qts $17.97, VR1 high zinc 5qts $29.08

Thank you BG for chiming in. I appreciate your help.

 

[twas_brillig]

Consider using Rotella T4 15W40 diesel oil - cheap, with high zinc. I can't swear to it but I think that diesel oil has heavier duty cleaning additives. If you're thinking of doing a second flush, consider taking it out for a drive and getting the engine fully warmed up etc. on your second one. I can't see how running for a short time with low zinc would have any real impact if the Rotella is expensive in your area (we're using the Rotella as our regular oil change at the moment). Give yourself a shiny new filter before the final oil change.
Many years ago, I had a flush kit in one of our vehicles where you hooked up the garden hose and ran fresh water through the engine as it was running. Dunno if those kits are available, but a thought.
I"d say 'have fun' but that wouldn't be appropriate, so - good fortune!
Doug

 

[BigGreen]

Emulsion on the top could be from condensation (short drive, reduced cranckcase ventilation)
For oil to turn white from coolant it does not need the engine running. To be sure check under valvecover.
I would be happy after draining oil that has no white and stop there.
For flushing and a short drive (until hot, to drain easy) a normal oil will do fine.

With a fillup and drain without debris in the drained oil, I would not fear for more debris
If so it will hit the pan first, have to pass the pickup filter and oilpump before ending in the filter.

Oil that is white must be disposed of, debris you can filter if you like
Without visible white or debris in the drained oil, it can be used again (like for flushing)

I would not use transfluid or oil for diesel engines

 

[LarryK]

I have a friend that is original owner of a 1968 Cougar with over 300,000 miles. Changes oil every 3000 miles. On every third oil change, puts in three oil and 2 trans fluid. Drives 500 miles and changes oil. We have taken pan down and checked bearings, no meaningful wear. So, must work. Right now I have 5 gts trans fluid in my GT6 and weasel pee in the cylinders. It is locked up, but by the time it warms up it will turn. Done it before.

 

[BigGreen]

In my family we use the saying

Find what you like and use it often

 

[Marvin Gruber]

Bought a boat several years ago with 305 chevy in it. PO had cranked it and said it then stopped suddenly, he checked the oil. It was like chocolate milk. He had not winterized it. Head was cranked. I bought the boat and replaced head. I bought the cheapest 10w-30 oil I could find. I filled it up, ran it for just a couple of minutes the first time. Did it again and ran it maybe 5 minutes. Did it the third time for maybe 10 minutes. By then it was looking clean. Replaced it with Castrol 10/30. That was 8 years ago with changing oil once a year at first of the season. I put around 100 hours a year on the boat.

 

[AUSMHLY]

Hello Marvin.
Thank you for chiming in.

Our Healey's should use a high zinc engine oil to protect the engine parts.
I'm enquiring about two things.
1) using or not using high zinc for the flush. (Does it matter for a 10 minute run time)
2) how long should the car run and at what rpm

 

[Marvin Gruber]

No engineer but have been restoring LBCs since 1974. I have used nothing but Castrol 20w 50 in all of them with no problem. Don’t see a problem either way with the flush. 10 minute run should be more than enough, you just want to get the engine up to temp. 1500/2000 rpm would be fine. The zinc is more important when engine is under load.
Marv

 

[Michael Oritt]

Addressing your questions directly:

1. Since you will be running the engine at idle or low revs for 15 or so minutes you should not need to use a high zinc oil.
2. 10-15 minutes at idle or low revs-your goal being to circulate the new oil through the system to capture any emulsified oil or other pollutants.

BUT:

Though it is unlikely to happen, rattling around in the back of your mind--probably when you are trying to go to sleep--will be the questions "Did I cause any damage to the camshaft lobes during the engine flush by not using a high zinc oil? How will I ever know? Maybe I should have bought the good stuff and now it is too late--I am screwed!" Ad infinitum.

The price differential between the cheaper oil and what you KNOW you would like to use is only a couple of dollars per quart and that times six will come to around $15.00. So what is a good night's sleep worth to you?

CONCLUSION:

Use whatever oil and filter you normally use, run the engine at idle or low speed for 15 minutes, drain the oil and change the filter and toss that stuff in the garbage. Sweet dreams!

 

[twas_brillig]

My 1999 Buell motorcycle (which uses a hotted up pushrod Harley-Davidson V-twin engine) recommends using the Harley brand of engine oil. If it's not available, then I'm to use a diesel rated oil, per the owners manual. Doug

 

[nevets]

I totally agree with Michael Oritt. Except don't actually toss the waste oil and filter in the garbage...I'm sure he meant to dispose of it in an environmentally responsible way.

 

[Michael Oritt]

Yes, of course and I only used the phrase "toss that stuff in the garbage" to mean that I can see no reason to keep the oil used for flushing for some future flushing, which would be akin to taking a bath in dirty water.

 

[BoyRacer]

I seems to me that you should be asking questions about why you blew a head gasket in only 500 miles. Warped head? Stuff that you put on the head gasket? Improper head bolt torque specs or tightening sequence? I think you have bigger problems than an oil change.

 

[AUSMHLY]

I seems to me that you should be asking questions about why you blew a head gasket in only 500 miles. Warped head? Stuff that you put on the head gasket? Improper head bolt torque specs or tightening sequence? I think you have bigger problems than an oil change.

BR, thanks for your concern. I've addressed that in my prior posts.

 

[BoyRacer]

Prior posts? I can't find them. Did you post them on a different forum?

 

[bdcvg]

Rislone. Follow the instructions. Don't over think.

 

[Legal Bill]

If no water-oil mix came out of the oil pan, I'm not even sure why you are doing a flush.