oil in cylinders (rebuilt engine)

[betaveloce]

Hi guys,

I have a serious problem with the engine that I had rebuilt by a specialist firm for my HPE i.e. It had everything including new bores (84,4 mm), pistons en piston rings. I put the engine back in a few weeks ago and it started fine and sounded very encouraging. Couldn't leave it running for long however, because we soon noticed a considerable amount of oil on the floor - it appeared they used a wrong gasket between the distributor and the camshaft housing.

I then changed the gasket and started the engine again, but I didn't even have the time to check if the oil leak was fixed, because suddenly there was a lot of grey smoke and the engine stalled and didn't start again. When I removed the plugs, I found that there was lots of oil (fresh, not burnt) in cylinder number 3 and 4. Also oil came out of the tube from the inlet to the air flow meter.

A friend suggested I may have overfilled with oil. I found it strange that I would have made such a mistake, but after a quick search on the internet I had to admit that the symptoms were there. So after cleaning everything up, removing the oil from the cylinders and draining the engine completely, I refilled it (making absolutely sure to not even go passed the minimum indication on the dipstick) and measured compression (which was ok). So then I started the car again, it fired up immediately, but after only 30 seconds or so, the exact same thing happened… Knowing that the problem was absolutely not that I overfilled the engine with oil, does anyone have any thoughts on what could be the cause here? I contacted the firm that was responsible for the rebuilt and they're coming over tonight to see for themselves, but I suspect the engine will have to come out again… 

[lukasdeopalenica]

Hi, if the compression is okay the only posible way for oil to enter cylinders is via valve stem seals. I cannot see any other option. If this is the case you will need just to remove the cylinder head.

[HFStuart]

I can only come up with four ways oil can get in:
Up past the rings
Via the headgasket oil galleries
Down past the valves
In through the intake

I'm inclined to agree that if the compression is OK (what were the results?) and you're confident it's not coming in through the intake then the only route is the valve guides. That said it would need quite a lot of oil to stop the car running and prevent it from restarting - they didn't miss the valve stem oil seals off did they? The only solution really is to take the head off and have a look.

[lukasdeopalenica]

It seems like there are no valve stem seals installed or at least they are badly loose (no springs?)

[betaveloce]

Thank you for your replies.

Compression was 11 / 13 / 13 / 11 bar (I think that's about 160 / 189 / 189 / 160 psi) on cylinders 1 / 2 / 3 / 4. Differences that could be explained - I think? - because of the fact the engine hasn't been run in at all.

But like I said, the oil was in cylinders 3 & 4.

The new pistons are the Stock+ ones from Vicks AutoSports Store by the way.

I agree that in through the intake (via carter ventilation?) or down past the valves are the two most logical explanations. Although if it came in through the intake, I would expect there to be oil in all cylinders, or not? And via the valves... I don't know; it's such a large amount of oil to come in in such a short time... The guy from the firm came down yesterday evening and was puzzled as well.

Anyway, today he called me to say I could pull the engine out and bring it back in, hoping they can find the problem on the bench. So that's what I'm going to do tomorrow. I'll keep you posted 

[lukasdeopalenica]

It would be perfect if you have 13bar at all cylinders, but still 11bar is not dramatic value, certainly not to let passing such amount of oil. As you suggested, if the oil is sucked through the intake system you will have it in all cylinders as the intake manifold serves for all four cylinders.
I bet the issue is linked with valve seals. Anyway I reckon how much oil you have had in a single cylinder... as oil is not compressible you can imagine what can happened to the engine when piston had tried to force oil in a closed cylinder head...

[peteracs]

Hi

I can only think of three possibilities...

Valve guide seals, though so much in a short time? (were the guides/valves replaced and checked for wear?)

Failed or incorrect head gasket

Failed head/not flat which couples with head gasket problem.

As Lukas says about the oil, you need to take the head off to inspect it at the least to establish the issue.

One comment, if this head has been rebuilt I would have expected the compressions to be much closer to each other.

Peter

[rossocorsa]

This volume of oil seems unlikely to be valve seals, on a rebuilt head the valve stem to guide clearance would surely not allow that kind of volume through? Also I suspect the oil in this area isn't under high pressure so I can't see you'd get enough to stop the engine. If the engine hasn't run I don't think compressions are a strong guide, beyond that they are not excessively low, as it all needs to bed in.

[betaveloce]

Now 100 percent sure the oil comes from the carter ventilation, as I turned the engine with the tube disconnected and it just gutted out 

Even more scary: when I pulled the engine back out of the car today, I got an unexpected shower of coolant... coming out of the exhaust 

I really don't know what they did to my engine but this is really turning into a nightmare (before Christmas!) allthough it certainly wasn't cheap 

Anyway, after Christmas I'm returning the engine so let's hope they can put it right whatever the problem is...

[capriblu]

Hope that your engine builders can find something obvious and that no lasting damage has taken place.

Given the oil in the bores then I would be cautious about validity of the compression figures; even a relatively small drop of oil down the bores can give artificially high figures and mask potential issues with rings.

The water in the exhaust adds another worrying dimension - Have you checked the level of coolant in the header tank?  Unlikely but suppose that there could be a possibility if the head gasket has failed spectacularly then this could result in over pressurisation of the crankcase as well as loss of coolant through the exhaust?   

[Neil-yaj396]

Head gasket fitted wrong way round or out of line? Would that expose oil and water galleries?

[HFStuart]

My thought too.

[rossocorsa]

I'd suspect completely wrong gasket used

[betaveloce]

Let's hope it's that simple (and that there isn't too much other damage inside...).

Anyway, engine is now ready to be taken back and they promised me that they would simply start all over again, so fingers crossed 

In the meantime, thanks for the input and merry christmas to everyone who cares about that 

[betaveloce]

Update: it seems that there were multiple issues:

- the oil being forced into the inlet through the carter ventilation was apparently being caused by a wrong gasket inside the carter ventilation pot.

- the water in the exhaust was apparently being caused by a wrong cylinder head gasket and a very very small crack in the cylinder head (right next to a valve seat) (although the head was tested...)

I brought them another head this morning and hopefully I should have the engine back by the end of next week.

Oh, and by the way: there are no signs of damage to pistons, valves or bores, so that's a relief 

[peteracs]

Update: it seems that there were multiple issues:

- the oil being forced into the inlet through the carter ventilation was apparently being caused by a wrong gasket inside the carter ventilation pot.

- the water in the exhaust was apparently being caused by a wrong cylinder head gasket and a very very small crack in the cylinder head (right next to a valve seat) (although the head was tested...)

I brought them another head this morning and hopefully I should have the engine back by the end of next week.

Oh, and by the way: there are no signs of damage to pistons, valves or bores, so that's a relief 

Good news on the bores, pistons and valves, but given the issues, how much confidence do you have this time...?

Peter

[betaveloce]

Good news on the bores, pistons and valves, but given the issues, how much confidence do you have this time...?

Peter

at the moment there's not much I can do but live in hope 

[rossocorsa]

As regards the oil coming up the breather is it possible that they omitted the small return pipe that goes down to the sump? I might be wrong but I vaguely remember something about that, maybe someone more tech minded can comment? The explanation of an incorrect gasket for this phenomenon doesn't seem right to me(??)   

[betaveloce]

As regards the oil coming up the breather is it possible that they omitted the small return pipe that goes down to the sump? I might be wrong but I vaguely remember something about that, maybe someone more tech minded can comment? The explanation of an incorrect gasket for this phenomenon doesn't seem right to me(??)   

I finally have my engine back. Just to make sure, I took off the sump yesterday evening (again...) just to make sure the return pipe was correctly installed and this was the case, so fingers crossed...

Don't know if I will have time this weekend to put the engine back in, but I'll keep you posted ;-)

[betaveloce]

Update: engine is back in the car for a few weeks now and this time runs as it should; have done about 100 miles so far.

Very happy to (finally) have the car back on the road!