PERFECTLY clean cylinders, no compression

jaguar
xk8

#1

Recently, after a long trip cross-country, my car wouldn’t start. My mechanic said it had no compression, and when he opened it up, he said the cylinders were “completely cleaned out. I’ve never seen anything like it.” He poured some motor oil in each cylinder and said that would solve the problem. It blew thick white smoke for a while – very embarrassing, but eventually it stopped doing that, and the car runs fine now.



But I have to wonder, first, what could cause such a problem? I’m suspicious that it might be because, on the road, I was having to use gas with a higher ethanol content than we get around here. And second, is it likely to happen again? Is there some other repair that I ought to consider? I use this car only for long trips, and really don’t want to get stranded in the middle of nowhere.


#2

Are you saying this engine was disassembled for the wash out diagnosis to be made? I would think that this was caused by the fuel washing out the cylinders but via an error in injection lenght or fuel pressure. I saw this happen on a 6 cyl BMW where the mechanic pinched (and thus grounded) the F.I. harness between the valve cover and the head.I do not believe the problem was related to ethanol content of the fuel.


#3

I don’t know about “disassembled” – that sounds like more than he did. But he removed, I guess, the manifold (? – I’m no mechanic and haven’t looked at an engine since my VW’s motor fell out on the highway in 1973) so he could see inside.

I don’t know what an F.I. harness is. How would an error in injection length or fuel pressure cause the cylinders (all of them, apparently) to get washed out, and would that be a software problem?


#4

In passing along what your mechanic did to your car you are leaving out lots of critical information. Just be happy your car is running now.


#5

There’s no way to look at the cylinders without removing the head…And I don’t know of any way of squirting oil in there either without removing the head…


#6

Well, the oil could go in via the hole for the spark plug. One could also get a really tiny window on the top of the piston through there. Perhaps a boroscope?

But either way, nothing about this makes sense. There’s no way that you dump oil in - regardless of where or how - and fix a lack of compression.


#7

I will answer your questions,fuel can wash out so much oil that all compression is lost(causing a no-start condition)and enough oil can be squirted back in through the sparkplug hole to get you back to where you are. F.I harness is “fuel injection” harness. A pinch or short in the harness can cause the injectors to just keep on squirting durning a start attempt (or several start attempts) and the sealing oil in the cylinder is washed out,this is what happened in my example.A borescope will provide a good enough image of the cylinder wall condition to detect damage. We used borescopes to check the damaged aluseal/nikaseal early BMW V-8’s.These engines lost compression due to poor engine block material (BMW claims it was a fuel sulpher content issue,made a lot of work that’s for sure).

Something similar happened some years ago when a friend beadblasted his small block Chevy cylinder heads (bead blasting is a cleaning process and he wanted to get the old paint off). This friend did not wash out the bead blast medium good enough and on the first start of the freshly rebuilt engine it fired off, ran about 3 seconds then quit. It took about an hours searching to figure we had lost all compression(we oiled it up and it started). It took another 3 months to figure out it was from the bead blast as in 3 months every bearing in the engine was worn out.


#8

Is there a way to check this fuel injection harness for pinching or shorts? (I assume all cars have this thing; this being a Jaguar I wouldn’t be surprised to learn that it uses some completely arcane thing instead. Nor would I be surprised to find that this problem is electrical in origin.)


#9

I AM happy it’s running now, but as I said originally, I take long trips in this car, usually six to twelve thousand miles at a stretch, and Jaguar dealers and mechanics are pretty thin on the ground in a lot of places. My reason for asking about it in this forum is to find out (1) if it’s something I need to be concerned about happening again, and (2) what I can do to prevent it happening again. I’ve said what I remember the mechanic telling me, but a lot of times when mechanical people talk to me they might as well be speaking another language. If there is something else that I need to pass on, tell me what. His shop is only a mile from my house and I have no problem in asking him for more info.


#10

There’s no way that you dump oil in … and fix a lack of compression.

This was exactly my thought when he told me what he had found and what he had done. And my second thought was, when all that oil burns off, won’t it be right back to the way it was before? But from Oldschool’s comment (above) I take it that there is supposed to be oil in the cylinders – “sealing oil,” he called it – so I infer that the problem is that, for some reason, the oil that’s supposed to stay in there is getting flushed out somehow. That makes sense to me in the abstract, even though I don’t know enough about it all to understand how or why it would be so. I mean, I don’t even understand where it would go, except into the exhaust, and (now that the oil has burned off) there’s no white or blue smoke coming out of it.


#11

This entire thread sounds like BS to me…


#12

Oldschool seems to have the best explanation. What to do now? If excess gas washed off oil in the cylinders then it contaminated the oil in the crankcase. If that oil is still in the motor, get an oil change.

You need to figure out how the excess gas happened in the 1st place. Are the fuel injectors dirty, old, leaking? Is the fuel pressure regulator bad and allow too much fuel pressure? Is there an electrical problem signaling the injectors to stay open too long? Troubleshooting the FI system is next on your agenda.


#13

Well, the oil could go in via the hole for the spark plug. One could also get a really tiny window on the top of the piston through there. Perhaps a boroscope?

Squirting oil into the sparkplug hole works…I’ve done it…many years ago on a truck that sat for almost a year.

As for scoping…I’m not sure how much you’d be able tell from a scope…

This is just doesn’t make sense to me. I’ve seen cylinders wash before…But that was caused by a carb running too rich. And when that happened…the cylinders go scared and you needed to rebuild the engine.


#14

Let’s assume that your fuel injection malfunctioned, washed your cylinders, you lost compression, and the oil squirted into your cylinders re-established compression.

At best, you had a temporary fuel injection failure. Given your driving needs, I’d be VERY concerned that the problem will repeat, stranding you in the middle of nowhere with a dead car.

At worst, the problem is more involved, and the oil was just a temporary band-aid.

Either way, you need to have your car diagnosed by an expert shop before you go on a long trip.

And get your oil analyzed before it’s changed to confirm it was a fuel injection problem. Your mechanic could be completely wrong and the oil squirting into the cylinders was just a coincidental ‘red herring’.


#15

I could go and look at what type fuel injection your car uses (but I might get on a list of people interested in Jaguars,only joking as my best friend is a 737 pilot and drives a very nice older Jag, he sure needs the income to keep it going) and then I would have a better idea what could cause a fuel flood of this magnitude. It is probably safe to say it was either a overpressure,a control problem (like the harness damage or a control unit) or leaking injectors. The problem I have with leaking injectors is I can’t see all injectors leaking down at the same time. Sure some degree of effort should be made to figure this out,starting with a review of known isues with the car.Is it at all possible this problem could have been induced by a mechanics error? what year is your car?


#16

I agree, this whole thing doesn’t really make sense. I think the mechanic might be wrong. So far nothing’s actually been diagnosed, just a quick treatment that appears to have worked.


#17

“six to twelve thousand miles at a stretch” ???
How many miles are on this car?
Do you randomly drive across the entire United States 3 times in a row?
If you do… Don’t do it in your Jag. Save your money on figuring this out and get another car.


#18

“six to twelve thousand miles at a stretch” ???
How many miles are on this car?
Do you randomly drive across the entire United States 3 times in a row?
If you do… Don’t do it in your Jag. Save your money on figuring this out and get another car.


#19

No idea on this one because I get the feeling the story is very inadequate as to what was done, etc. I’ve seen engines with washed down cylinder walls and a refusal to start but never one in which there was quote, “no compression”. Way low as in 40 to 60 PSI, etc. but never zero, assuming that is what is meant by no compression.

If there were a problem with the fuel injection causing the cylinder walls to become washed down and leading to a total or near total loss of compression then the engine oil should be absolutely reeking of gasoline.


#20

Unfortunately, the mechanic I took it to is the foremost Jag mechanic around here. We do have a dealership in town, but I don’t have as much faith in them as I do in this shop.

How do I get my oil analyzed? Who do I take it to, and what do I ask for?