Hello,

So long story short, my 2000 4.0L Jaguar S-Type blew a head gasket and needed a new engine. The job was done over the coarse of a month by a private mechanic who put a used one in with 63k miles on it. Ever since I got the car back, however, it has not been the same. First of all (and a separate issue) the upper timing chain tensioner is bad so it makes a ticking/rattling noise while it idles. The real issue, though, is the amount of smoke it produces. At startup (less on a cold start) it will sometimes puff whitish smoke out of the tailpipe (which to most points to failing valve seals). On hard acceleration, it will sporadically shoot smoke (more white than blue in color) in varying amounts. Sometimes it will be only a small amount, others it will be a cloud big enough to cause the car behind me to momentarily loose visibility. From what I have gathered from doing multiple hard accelerations in a row, after letting the car sit, is that is smokes more on the first pull and less on the following pulls. I have monitored coolant and oil levels and noticed a bit of loss. The underside of the engine near the oil pan is wet with oil, and it does seem to be dripping very minimally only for the first few minutes after it has been parked.

(Although I am no mechanic, if i had to guess, it would seem to me that a PCV valve could be failing. This would explain the whitish smoke and access engine pressure causing it to leak oil. I can't, however, find the PCV in the car.) If anyone has any kind of insight as to where the valve is located/if it has one and what else this could be please let me know.

(For all who are wondering YES the mechanic did refund me for the job, however, he has refused to touch the car again.)

 

Almost no reports of blown head gaskets on any of the three different S-Type engines (3.0, 4.0, 4.2). Do you know what caused yours to fail?

 

You probably should not drive it with a bad cam chain tensioner .
Very risky .
Could the smoke be from oil on the exhaust caused by this oil leak ?
you would want to hope it's that or you should return the engine through the guys wall .
A failing pcv flags a check eng light .
I don't think it's that . Does your old engine have spare parts to try .
The cam cover has a gauze in it to seperate the oil through the pcv.
I've seen a thread a wile ago discussing 4.0 xkr's some times having the gauze missing causing oil consumption .
It looks like you said coolant is disappearing as well . And if it's not on the ground it's not looking good for your new engine .

 

Unfortunately no one is 100% sure what caused it to fail. We have pretty much assumed, however, that various instances of overheating (most from the previous owner) is the main culprit.

 

It does have a check engine light, however, I have not had the time to get it scanned. I realize that this is always a good first step in any self diagnostic and as a Jag owner, I should probably have an OBD2 scanner with me everywhere I go. I doubt an oil leak onto the outside of the exhaust is causing an immense amount of smoke to come out of the tailpipes. Is it perhaps possible that it's leaking and pooling up somewhere in the exhaust manifold?

Thanks

 

I would take the car to another garage and get them to check to see if there are any hydrocarbons in the expansion container. This can be done very quickly.

.

This will show if the head gasket is blown on this engine as well.

If so get on the phone to your lawyer because the workshop is responsible if they sourced the engine.