A friend of mine has been having mysterious troubles with his 1994 calibra turbo 4 x 4. Vauxhall have had the car for the last week and they can\'t seem to work out what is wrong with it. His description of the problem is below:
The car smokes when it feels like it! Usually it needs to warm up first or after a run when hot. Colour is dirty white/grey. The exhaust is then black with soot. When idling it will start putting out a little then quite quickly build up to a lot. High revs either clears it (and then it starts again) or just lets lots of smoke out. I have driven slowly in queues on the motorway for ages and nothing comes out (the exhaust is then very clean - no soot). Then at other times I start it up and it smokes. Usually it clears and then nothing for ages. The emissions are either off the scale (!) or just outside limits, again they keep changing.
One other thing, the electrics did something interesting. The engine warning light started coming on intermittently for say a few seconds when under load at speed. Then it did it when doing 30 (this has lasted about 10 months) then stopped doing it altogether. Vauxhall said the TEC test was clear but it may be the lambda sensor. However they now think that the sensor is ok as there is no tec reading. Then a few weeks ago the 4x4 warning light came on (and remained on) after the car had been idling for a few mins although when switched off and then on again and
driven it was fine. It did it again on a second test but has not done it since. Vauxhall have not been able to repeat the electrics problem but have seen the smoking problem. They say the turbo has a tiny movement in the shaft but nothing that should cause concern.
The car has a high mileage (157k) but has had regular service with semisynthetic oil and all other oils have been changed at recommended times.
Any ideas?
teabelly
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Coolant temperatur sensor could be the culprit or more usually the wiring to it.Is this the 8 or 16 valve engine? Either way the sensor will be on the inlet manifold close to the cambelt end, blue in colour with two wires going to it. Unplug the connector and roll back the rubber boot and carefully inspect the wires, any fault will be obvious.
Carefully check the earth wires from the battery to the body and body to engine. There are also a few earths to check which are bolted to the cylinder head.
A final thought is that the evap system may be allowing neat fuel to be drawn into the manifold. A fault on the valve may trigger a fault code but not always. Unplug the pipe from the evap canister after the valve and plug it engine side and see if that has any effect.
HTH Andrew
Goodwood, aaaaahhh!
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Thanks for the info. It is the 16 valve engine. My friend has been looking under the bonnet intently and didn't find the coolant sensor but did find a pipe to the manifold that was broken that had a valve in it. He said it seemed just to be there to let more air in. This may or may not be the evap system that you mentioned but either way it wasn't connected properly. He completed the connection with another bit of pipe and that has removed some of the other longer term running problems like lurching when the turbo kicked in and has made the car run a whole lot smoother. A proper replacement for the missing pipe is on order so this may just solve the problem by itself or further fiddling may be required!
teabelly
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