Hydrolock

[SBK930]

With the failed compressor seals allowing oil to enter the intake plus the fuel which has caused hydrolock, could any damage have been done by cranking the engine over ?

[turbo owner]

Originally Posted by SBK930

With the failed compressor seals allowing oil to enter the intake plus the fuel which has caused hydrolock, could any damage have been done by cranking the engine over ?

I doubt it, take the plugs out and crank it over.

[infraredcalvin]

I did that once, luckily a weak battery, removed plugs, charged the batt, no issues...

[Tippy]

BTDT on another engine. Bent a conrod. Doubt you'd bend the stumpy ones in a 911.

[SBK930]

Originally Posted by SBK930

With the failed compressor seals allowing oil to enter the intake plus the fuel which has caused hydrolock, could any damage have been done by cranking the engine over ?

OK, I have pulled the plugs and fuel relays, cranked it over and had oil spray out of the right side cylinders and no sign out the left side.
Is this normal???

[SBK930]

Originally Posted by SBK930

OK, I have pulled the plugs and fuel relays, cranked it over and had oil spray out of the right side cylinders and no sign out the left side.
Is this normal???

Have just done a compression test on thr right cylinders and readings are around 115psi.
So is this OK as far as compression goes ???

[SBK930]

Should mention the test I did while all plugs removed and just cranked over the engine a few times on each cylinder, the left and right appear to be around the same give or take 5 psi.

[Rawknees'Turbo]

Oil in the combustion chamber, to the point where it shoots out of the spark plug hole, is not normal - I assume that it is there due to the turbocharger problem, but don't quite understand why it is only on one bank.

I don't know what proper cold PSI compression numbers are on these engine (I never do compression tests like that on engines, just leakdown test . . . not saying it's bad to do compression test, though), but I know the number would be low since static compression ratio is only around 7:1. The fact that the cylinders are similar to each other is definitely good.

Refresh my memory on how you have the crankcase and oil tank vented - is it a stock setup or custom/modified?

[SBK930]

Originally Posted by Rawknees'Turbo

Oil in the combustion chamber, to the point where it shoots out of the spark plug hole, is not normal - I assume that it is there due to the turbocharger problem, but don't quite understand why it is only on one bank.

I don't know what proper cold PSI compression numbers are on these engine (I never do compression tests like that on engines, just leakdown test . . . not saying it's bad to do compression test, though), but I know the number would be low since static compression ratio is only around 7:1. The fact that the cylinders are similar to each other is definitely good.

Refresh my memory on how you have the crankcase and oil tank vented - is it a stock setup or custom/modified?

I think it's fairly stock.
There is no charcoal canister between the scavenge pump and tank.
The drip/catch can from the turbo is vented to the air cleaner.
And I would say that the crankcase is vented into the oil tank.

Am about to fire it up to check the engine oil pressure but I doubt it will have a chance to reach too much temperature.

[SBK930]

Here is what happened after cleaning the plugs, cranking it with the plugs out to remove hydrolock and cold cranking test for compression.
Is the engine oil pressure OK considering it is stone cold start up. It is around 45psi.

Obviously all the smoke is from my dud rebuilt turbo.

https://m.youtube.com/watch?v=KPlhkls3Khs

[smurfbus]

You may have a modified oil pump with high pressure right from idle?

[SBK930]

Originally Posted by smurfbus

You may have a modified oil pump with high pressure right from idle?

Hi smurfbus,
Why a modified oil pump?
Not that it would surprise me.

[smurfbus]

Some cars like mine have engine mods to make it handle extra power and rpms. Mine has carillo rods and stronger oil pump and I see high oil pressure from idle to high rpms.

[Alan L]

A lot of the smoke is probably oil thru the system - eg muffler, headers, burning off. If it got as far as the cylinders in big volume it probably made it further. Like Rawknees, I don't know why it is only on one bank of cylinders. This is weird - you have a common intake (pancake) manifold. You will probably have oil all thru the intake (intercooler) system too, which will take some time to clear, and for the sake of the IC performance, should be cleaned out.
The other strange thing is your high idle oil pressure does not fluctuate as you increase revs. It should have jumped another bar at least. Weird.
The compressions are probably OK , but not really definitive of anything - with an oil soaked engine.
You can probably conclude no bent valves and likely no rod damage - but a proper running warm engine would be more conclusive for the latter.
For me, I think I would be stripping the intake system down - to track the oil and clean it out. Then I may have a better idea why it has only ended up on one bank of cylinders. Presumably you had one bank of oil wet plugs and one bank of dry plugs?
Alan

[SBK930]

Originally Posted by smurfbus

Some cars like mine have engine mods to make it handle extra power and rpms. Mine has carillo rods and stronger oil pump and I see high oil pressure from idle to high rpms.

I suspect that after running it for a while to warm up that the oil pressure will drop.
However I will not be able to run it for long as the oil pushing through to combustion will start to suffocate the firing.
So far I have an oil circuit that appears to work, not overly high engine oil pressure, OK compression at the cylinders, and turbo rebuilds that do not last more than 5 minutes.

I am trying to rule out any cause for the rebuild to fail, as they are a Borg Warner licenced repairer and they do VSR balancing. I have suggested the parts they use are the issue, but they assure me that is not the case.

The only other area I have considered is if there is a leak at the junction where the metal line from the drip/catch tank from the turbo meets the metal line to the scavenge pump. But how do I test if it is sucking air and not the full volume of oil ?

[Alan L]

To test the scavenge pump you need to disconnect the line to the pump at the catch tank. The turbo oil flows thru the turbo and tank to waste. You collect it in a container. You then fit a plastic hose from your disconnected scavenge line to the container. The run engine. The scavenge pump should more than keep up with what is collecting in the container, ie should be sucking it dry.
Alan

[SBK930]

Originally Posted by Alan L

To test the scavenge pump you need to disconnect the line to the pump at the catch tank. The turbo oil flows thru the turbo and tank to waste. You collect it in a container. You then fit a plastic hose from your disconnected scavenge line to the container. The run engine. The scavenge pump should more than keep up with what is collecting in the container, ie should be sucking it dry.
Alan

Hello Alan,
I have done the scavenge pump test to verify it is working satisfactorily. https://m.youtube.com/watch?v=c4R8Tv207u0
Just do not know if there could be an issue between the turbo and the connection to the scavenge pump line. If there is it could be allowing the oil to build up.
I think due to the flow through the intake the bulk of the oil ends up in the first cylinder on the right side as all plugs had some oil.

[SBK930]

ps: this is doing my head in.
As at this moment I fear I may need to buy a new turbo but do not want to install it only to have it fail due to some underlying issue.

[Alan L]

If there was a air leak at the tank connection to scavenge line, it should leak oil too? On to your floor.
Do you have the check ball (9mm I think) in the oil line - below the idiot switch? This is to prevent siphoning flow in to the turbo when scavenge pump not operating. Not sure how this would put oil into your intake tho. UNLESS the turbo was flooding with oil when standing, and some gets sucked up the intake side while the scavenge pump is clearing the excess. If it was flooding then on start up you would be pushing more oil into an already flooded place before the scavenge pump can clear the resevoir.
It might be worth running it for a bit (few minutes, to scavenge all oil out of tank), then shut it down. Then check 12 hrs later if catch tank etc is full.
Alan

[Rawknees'Turbo]

^^^

Just looked at your vid of the scavenge pump test - looks like it is functioning perfectly to me, so that rules out a problem with the pump or any of the oil lines to and from it (an air leak in any of those will show itself in the pump test).

If this were mine, at this point I would feel very confident that the turbocharger is to blame and that the rebuilding place does not know what they are doing (despite their reputation). But I will admit that I too would be having my "head done in" by this - lots of money involved to just go throwing parts at a problem and hoping for the best. BUTT that said, the scavenge system checks out, there's no way that all of the oil is originating at the air intake (from a wildly overfilled main oil tank and passing from the tank to the air intake by way of the tank breather hose), correct? If not, I don't see how it can be anything else than the turbo at fault.