Oil Pressure Fluctuates and Breather Pipe has Creamy Gunk

[caddsource]

1. At cold start oil pressure is about 40-50 psi. No problem.

2. At warm up the oil pressure begins to drop and sometimes fluctates to a point it reads zero on a drive.

3. Checked oil in sump, looks normal and is full.

4. Check the air cleaner and noticed that the breather pipe was full of
white creamy stuff. Also, the air filter had what looked like water.

5. Additionally, the air filter chrome housing also had what seemed like water residue. (See photos links below)

6. Further inspection showed that the right lower and rear of the engine block was moist with water.

7. I think the head gasket may be the problem.

Any feedback would be greatly appreciate?

Links to Pictures

http://cid-e9c9fed8edc38859.photos.live ... e.aspx/XKE

[christopher storey]

There is nothing very unusual in the photos . Unless the car is regularly run for prolonged periods, by which I mean 35 miles or so at a stretch, this sort of emulsion is not unusual , although it can also be a sign of wear leading to piston blow-by . To check the head gasket , first check is a compression test with the engine hot , when at cranking speed with full throttle at sea level you would expect somewhere between 125 and 175 lbs depending on CR and condition. The important point to look for is consistency i.e. all cylinders within 10 and at the very most 20 of each other . Gasket failure usually shows itself as 2 adjacent cylinders having markedly lower readings, but occasionally, it can show itself with a single cylinder being low . You can also get small test kits which check the coolant for exhaust traces

The oil pressure is likely to be a different problem . The very first thing to do is to find a mechanical gauge and check the readings on the electrical setup, which are notoriously prone to be inaccurate . This is done by plugging a gauge into one of the ports in the oil gallery which runs down the RHS of the block . If you are getting very low pressure when hot, then it is possible that it is a failure in the pressure release valve or filter setups, but I am afraid that a more likely cause is excessive bearing wear

[ChrisC]

I am with you Chris.... the two symptoms together smack of a head gasket failure. I would say the compression test would be the final tick in the discovery. If two adjacent cylinders are lower than the others then its head off time.

Certainly dont run the engine anymore until you have tested this and if you are lucky the bearings *might* survive...

[Heuer]

If the head gasket has gone I would expect to see some evidence of it in the header tank water as a creamy surface scum.

[caddsource]

First of all, I would like to thank all of you for your guidance.

Tests

1. Compression test.

2. Test the oil pressure at the sending unit. (I did order a new one just in case pior to this posting)

Notes:

1. The water in the header tank is very clean with no abnormailities.

2. Oil in sump is very clean as well with no abnormal discolorations, etc.

3. I am still stumped with moisture at the right rear side and back of the engine block which steams the middle lower windshield and fuel gauge. This is definately water vapor/steam.

4. I found out the the guy who recently changed my oil, used 5W-30 where as I usually use 10W-40. Might this be related to a drop in oil pressure?

In summary, I will conduct the above tests as recommended.
But still think that the head may need to come off and hopefully it will be a matter of just replacing the head gasket with no machining involved.

I am pretty mechanical, but have never removed the head of an XKE. Any advise on this prior to starting.

[JEP41]

I had a similar problem on an XJ6 funnily enough when I was living in San Diego, but mine showed the water vapour in one exhaust pipe also which, with the plugs removed after leaving the car standing over night I found water in one cylinder conclusive of a head gasket failure. Again on my MK2 I had a leak from just the back of the engine (tin Head Gasket fitted) which stopped when the engine warmed up. No compression issues this time so I added Bars Leaks and had no further problems.

[ChrisC]

TIPs and not a sequence of work....

1. Set the engine to top dead centre before you do anything else. That way you can sure the camshaft setting will be close when you disconnect the timing chains.
2. Buy / borrow the cam setting tool and a timing chain tensioner - nothing worse than discovering you cant get the chains tight...
3. Sometimes the head studs corrode and stick to the head so the head wont lift when you undo all the nuts - so pour a little PlusGas around the headstuds and let it soak for a while before trying to lift the head.
4. you will probably have to hit the head with a soft mallet a few times so that it lifts despite doing tip 3
5. And a lesson learnt - when you take the cam covers off - push a lint free rag into the area around the timing chain (inside the head) - now if you accidentally drop the bolts that hold the chains to the cams - the worst that will happen is the bolt falls onto the rag and NOT into the depths of the engine. Guess how I found this one out :(

Its not a hard job but it takes some time... have fun

[christopher storey]

If you are getting water/steam inside the car, then the likely source is the heater transfer pipes which on many cars are inside the bulkhead . If you car is of this type then you will find that there is a short hose from the inlet manifold area which goes directly backwards and fits onto a spigot which is the front end of the pipe going into the bulkhead. These pipes are a PITA to change , and if this is your problem, many people effect a fix by using a longer rubber hose running across the back of the engine to connect the manifold to the heater valve inlet

[PeterCrespin]

4. I found out the the guy who recently changed my oil, used 5W-30 where as I usually use 10W-40. Might this be related to a drop in oil pressure?

40-50 isn't great when cold - it should be showing 60-ish - and as that is relief valve setting the actual pressure would be more. So 40-50 is not 'no problem' from cold, as you started out by saying. It indicates a marginal situation if the pressures are real.

Meanwhile the oils you list above are likely to be the cause and whoever put 5-30 in your car should never be allowed near it again as they obviously have no idea about old-tech engines. Drain the 5W-30 oil, save it for a modern car and put the correct 20W-50 in your Jag. See what pressures you record and go from there.

5W-30 - give me strength!

[Larry Wade]

Rather than a normal compression test I strongly recommend a leakdown test. That will tell you if you have a leak and often where to. A compression test says more about the ring seal than anything else. I've seen cars get decent compression test result (e.g. 165 psi) despite having blown head gaskets.

Larry

[caddsource]

Just want to thank everyone for their valuable input and guidance.

Compression test results are as follows:
1-130
2-145
3-135
4-140
5-135
6-135

Will report back oil pressure after oil chnage - 20W50.