Hi.
Iīve tried looking around your forum but havenīt found anything just like mine problem.

I bought the car with a blown headgasket, coolant got in the cylinders.
We fixed everything but thereīs still this problem...

The problem is that the car runs great but it smokes A LOT, like "where did the road go".
It doesnīt smoke right from start but starts smoking after awhile, it seems to be white when idle but blue:ish when reving.
And the amount of smoke when reving is A LOT.
The "condens" that comes from the excaust tastes like coolant but where does the hint of blue smoke come from?

How much coolant can there be in the exhaust from the faulthy gasket?

Havenīt been driven more than about 20kilometers after the repair.

I havenīt noticed anything wrong with the oil or the coolant, the levels of both of them seems okay(maybe because of that it hasnīt been used?)

Any good or atleast ideas where to find the problem???

 

Hi Ulf,

Welcome to the Jaguar Forums. It's great to have you with us, but I'm sorry to hear about your troubles.

White smoke that tastes like coolant is highly indicative of coolant making its way past the head gasket into one or more cylinders. When you replaced the head gasket, did you notice any erosion in the surface of the head? All three times I've done XJ40 head gaskets I've found erosion in the head between a coolant jacket and cylinder. I've repaired the erosion with J.B. Weld epoxy and those repairs have lasted as long as the new head gasket.

Another possibility is that the head was warped and is not sealing properly. Did you check the head for warpage?

A very remote possibility is that a heater hose was reconnected improperly and is feeding coolant into the intake manifold.


The short answer is, "All of it."

Regarding the blue tint to the exhaust smoke, we would tend to think of oil as the cause. When you replaced the head gasket, did you also replace all 24 rubber valve stem seals? The most likely source of oil in the cylinders is oil that leaks down the valve stems from the top of the cylinder head, and the rubber seals reduce the amount of leakage, at least until the rubber hardens. Because of the tilt of the engine, the oil tends to leak down the exhaust valve stems more than the intake valves. This is the cause of the typical "puff of blue smoke" at start-up on these cars, but since you aren't experiencing start-up smoke, I'm not sure if the valve stem seals are your problem.

Something else that occurs to me is that if a heater hose was connected to the crankcase breathing system by mistake you might get some cross-contamination of coolant and crankcase oil vapors. When you replaced the head gasket, did you disconnect all the hoses on the intake manifold, or did you just remove the air intake plumbing and tie the manifold away from the cylinder head?


It doesn't take much coolant or oil to produce smoke in the exhaust. It seems possible that 20km has not been enough running of the engine to expel all the coolant that had found its way into the cylinder, and possibly the crankcase, oil passages, etc. But you would expect the smoke to begin as soon as the engine was started. The fact that the smoke comes after the engine has been running awhile suggests that perhaps it is happening after the coolant thermostat opens or some other event is occurring.

Sorry I don't have any better ideas, but it would be definitely worth double-checking all your work. Hopefully some of our other members will have some ideas.

Please keep us informed. And in the meantime, please visit the New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum and post an introduction so we can learn something about you and your Jag and give you a proper welcome.

Cheers,

Don

 

One thing I forgot to mention is that I took it to the ("road legale test", donīt know whatīs itīs called in english, sorry).
But it passed the emission test but the inspector didnīt approve it because it smoked to much????
So I also think that the blueish is the oil from the valve steams(since I didnīt replace them, but why isnīt it smoking at the start) :stupid

 

I have to put my 2 cents in- as usual because it might be something I would do- Is it possible to put the gasket in upside down? If so, would it make those problems?

 

Fortunately, I think it's unlikely that you or any of us would install the gasket upside down because the gasket is asymmetrical, with one end of the timing chain opening longer than the other and a small oil port opening at one of the opposite corners. It would be immediately obvious if it were not oriented correctly:


Cheers,

Don

 

another cause of ' white ' smoke, and lots of it is the engine vacuum from the plenum can be drawing in ATF fluid from the gearbox, this is because the vacuum modulator seal is letting oil by and the engine is sucking it up

this does create huge amounts of white smoke

BB

 

BB,

That's a good tip, but the ZF 4HP24 transmission in a '94 XJ40 is electronically controlled so there is no vacuum modulator.

Cheers,

Don

 

good point

i have only had my 1994 3.2S for two weeks now, lol

BB