Exhaust manifold gasket - VK Calais EFI

[85_Calais]

Specs: 85 VK Calais, 6 cylinder, EFI, dual fuel.

Took my car to the mechanic last week because it has been running really rough on petrol. Initially I thought it would be the injectors becoming clogged from not running on petrol enough. Have run an off the shelf injector cleaner through it but it hasn't made any difference. Lately it has been starting to sound a bit dodgy running on gas.

I took it to the gas mechanic thinking it would just be needing a tune, but he said there is a hole somewhere in the exhaust system and that the injectors must be clogged. The next mechanic I took it to said the exhaust manifold gasket needs replacing. He said this should fix the rough running on petrol and that I'm not noticing it as much on gas because the fuel mixture / oxygen levels / octane levels are different.

Does this all sound plausible? He could not guarantee that fixing the gasket would fix the rough running, but given he quoted $260 for the repair, I'd like to be reasonable sure it will fix the problem. I tried fixing it myself yesterday but it's way more complex than what I'm used to and they tried to fit way too much under the bonnet when they made these cars, so no room to move!

[vkberlina]

Sounds possible as the intake & exhaust share the same gasket.

Also your headers could be warped causing an exhaust leak so be prepared to spend money on new headers if required. There is no real way of telling untill they take them off your head and put a straight edge to them.

As for money gaskey should be about $35rrp I wouldnt think anything more than that, plus I think it shouldnt take anymore than 2 hours to remove & replace on a petrol only EFI. so the price could be about right, but you do get what you pay for so having said that they will probably be very thorough with the job and may take 3 hours esp with cruise control & gas conversion gear in the way.

When I had my EFI 202 in my car I used to have the whole engine & gearbox out in 1 1/2 hours and took 3 to get it back in.

cheers
Scott

[85_Calais]

Thanks Scott.

Turned out to be a crack in the extractors, which they have welded back together - an $80 repair rather than a $260 one that wouldn't have fixed the problem anyway. Goes to show the value in getting a second opinion.

I still have the problem with running rough on petrol, but it runs fine on gas so will just take it to an EFI specialist at some stage.

Anyone in WA with RAC roadside assistance - turns out you get a free fault diagnosis each year with your policy. Would definitely recommend taking advantage of this before taking it to a mechanic and committing to expensive repairs!