just did an engine swap in a 2000 vanden plas. oil apprears to have gotten milky. Is this a bad head gasket? any other ideas? also idles rough but is fine over 3000RPM's

 

Gotta resolve the 'latte' issue first. Historically, foamy oil=head gasket.

 

This^^^ H2O/Coolant+Motor oil= Chocolate milk shake...

 

head gaskets. thats what I was thinking. compression test was good though. weird.

 

Are you getting any oil with in the oil fliter/air meter pipe?

If you are, and the oil filler cap is showing signs of milk shake then it wont just be the Head gasket. Jags where still using Nikersil liners up to Aug 2000 and milky oil at the air filter could mean that the coating is worn and oill is being blown in the air drag.

How much oil are you going through?

Does the car start with out any rough ideal the first time you fire her up?

 

"oil fliter/air meter pipe" guess I am not sure where this is. Is this the 6" tube running from the valve cover to the intake snorkle? If so, yes. and yes, there is some oil in the air intake tube and inside the intake manifold past the throttle plate.

The oil is only slightly milky. Not like what you see on a boat when the block freezes. I really don't think it's headgaskets as the compression on all cylinders is good and the oil that was in the engine when I bought it was clean. Actually, if you let the car sit for about a day the milky oil goes away. Seems like maybe moisture build up or something else. The milky oil is showing up on the bottom of the filler cap and in the main breather tube to the intake snorkle. Car starts and runs fine for about a minute then starts to idle rough. If you drive it and keep the RPM's above idle speed then it runs perfect. No smoke either.

 

A few questions might help to guide diagnosis going forward. Is the new engine new, rebuilt, or used? If used, how many miles on the "new" engine? When did you swap engines? Did you open up the new engine to change tensioners or other parts? How long did the new engine sit idle before you put it in your car? Where did it come from? Where are you located and what was the weather like when you did the swap? What parts did you transfer from old engine to new, if any?

I know, a lot of questions, but given the compression test and idle only condition, I'm leaning more towards moisture in the engine that will take some time to burn off. If you used the old intake pipe and breather hose, throttle body and TB elbow, do you know whether the oil came from the old engine or new engine?

I recently swapped engines in my XJR and got some milky oil early on that cleared after a couple of long drives that got the engine good and warm. The replacement engine had been sitting in Florida for 9 months and the swap took place in south Texas during the foggy season, during which time I had the valve covers and front cover off for a significant amount of time. A lot of opportunity to build moisture.

Though compression is good, probably want to do a cylinder leakdown test and see if you are getting air out of the full load breather (where the 6" hose is from the passenger bank valve cover), exhaust, or in the coolant resorvoir. Depending on the results, may consider doing one or more of the following: radiator pressure test, exhaust analyzer or block test (can get a block test kit from NAPA for about $40 or have a shop with an analyzer do it), vacuum test, fuel pressure test. Might also want to do a good cleaning of the MAFS, throttle body and elbow, egr valve, and part-load breather. Also, you can run the engine and pull the full load breather hose off the full load breather and look for blow-by, which will look like vapor from a tea kettle, coming out of the breather hole. Still a lot of possibilities to explore before condemning the head gaskets

 

It's a used engine. about 110,000 miles. No idea if the timing components have been replaced. Came out of a 2000 XK8. They said it's been on the shelf about 3 months. Live in WI. Swapped about 2 weeks ago. Weather was about 30 degrees and probably somewhat humid for winter. Engine also came from a salvage yard in WI. The engine came with a full pan of normal looking oil which I drained and refilled with new oil filter. Once I got it all installed and noticed it was running rough I started looking at what would cause it. Old engine ran smooth but had a really bad rod knock. I used everything off the old engine including the throttle body, air intake tube, spark plugs, coils, knock sensors, and wiring harness. Left "new" intake manifold, injectors, cam sensors in engine. Seeing that it ran good before I did the swap it leaves me to believe it was something from the "new" engine giving me problems. To tell you the truth I am not so worried about the slightly milky oil as you say it may burn off. I am more worried about the rough idle, P0300 and P1316 codes that appear after idling for a few minutes. I am leaning towards the timing tensioners now and am starting to wish I would have swapped those out before installing the "new" engine.

 

Bear in mind that head gasket doesn't necessarily have to leak from cylinder to water jacket, hence good compression on all cylinders. You could have leak from oil passage, which is high pressure, to a water jacket. That could be where the gasket is bad at.
Just my 2 cents.

Alan.

 

Very true, except I am getting water in the oil and not the other way around. Is oil pressure higher than hot water pressure?

 

Radiator pressure cap is around 12-14 lbs, oil pressure is around 40 to 60. Yes, oil pressure is higher.
I would as a check, open the oil drain plug and VERY slowly pull the pan plug out just a little and see if any water comes out. Oil is lighter than water so if you have water leaking into your oil, water should come out first, if not then the somewhat milky oil could be from condensation. Have you tried changing the oil again and see if the problem goes away?
Have you tried pressurizing the cylinder for a leak down test?

Alan.

 

When the engine is shut down, oil pressure goes away, yet coolant pressure remains for some time. It is possible for coolant to get into the oil gallery during this period through a tiny leak in the head gasket between oil gallery and cooling passages. A cooling system pressure test will confirm if this is the case.

 

I have not changed the oil again. I will check to see if there is any water at the drain plug. Maybe a second oil change will do the trick.
Will a radiator pressure check work on the Jaguar system as it does not have a standard radiator cap?
What is a "block test kit"?

 

Hmmm, I have not tried with the Jag, so you have me at a disadvantage. I would hope that, somewhere, there is an adaptor available that would fit the Jag's cap configuration? Else, modification of an extra cap would certainly do the trick, if a bit cumbersome and labor intensive.

 

I used one of the Advance Auto Parts 'loaner' coolant system test kits to find a very small leak that left no traces other than the 'low coolant' message. It was an impressive setup with 21 adapters to fit any system on the planet. Of course, the one that fit the Jaguar was the 'universal' swelling type but it did seal and did its job.

The 'loaner' program means you buy the kit, in this case, $180. When you bring it back, within 30 days, they credit the full purchase price plus tax back. Time your credit card bill cycle and you are never out a penny. Great service.

 

is there any warranty on the engine??.U may have a purchased a problem engine. I unerstand that there are loads of factors to take into account with the change over but i would still lean, that if you are getting oil in the air filter pipe then the Liners are worn. Jag can do a check for you with the VIN number to see if the engine is built with Nikersil liners.

 

I am pretty sure the engine is bad either due to head gaskets or timing chain and yes there is a warranty but that doesn't cover the time for me to swap it out. Nothing better then doing the same job twice but that may just end up being what happens.