Overheating - is it the head gasket?

[Nikkie]

I have a 1998 Holdon Commodore executive V6 automatic and a few weeks ago all of a sudden after driving for 5 minutes the dashboard light up and read hot and the temperature gauge had shot right up. We pulled over straight away and got towed to a garage where they pressure tested the radiator etc and said there was a slight blockage and a slight crack so we had the radiator replaced. Since then we have driven from Kalgoorlie WA to Melbourne and have been driving around fine until this morning. All of a sudden the temperature gauge and dashboard did the same thing so we pulled over and checked the engine coolant, it was somewhere between min and max so we topped it up and the coolant leaked out of one of the hoses as we topped it up so we pushed it back in and it stopped leaking. We then drove the rest of our journey, at first the temperature started to rise above half and then all of a sudden dropped back down to a quarter and was fine after that. However this evening after being in the car for 5 minutes the same thing happened and the dash said hot so we pulled over and got towed to a garage. It's at a holden dealers but I am worried it is going to be the head gasket and cost a fortune. One of the blokes at work took the oil cap off and looked underneath and said there was water so it was likely to be the head gasket and to just get rid of the car. Does anyone have any ideas what it could be?

 

[Brett_jjj]

Its most likley going to be the inlet manifold gaskets leaking coolant into the engine. This is a very common problem with these V6's, but luckily its fairly easy and fairly cheap to replace these gaskets. These engines rarely blow head gaskets unless theyve been badly overheated and driven hot .. Also there seems to be a lot of mechanics around that make the mistake of thinking its a blown head gasket when its really a leaking inlet maifold gasket. Id say there'd quite a few people around who have replaced their engine when they didnt really have to due to misdiagnosis of this problem..

 

[luckyvt94]

+1 on the intake manifold gasket. My vt did the same. Replaced the gasket. didn't use a drop of coolant the rest of the time I had it. Cost me $660ish but I also had water pump, radiator cap and a wheel bearing done at the same time

 

[Nikkie]

Thanks! I am waiting to hear back from the Holden garage this evening and hoping that it is the inlet manifold gasket rather than the head gasket. We haven't driven the vehicle hot and whenever the temperature goes up we pull over and wait. How can I be sure that the garage aren't getting it wrong if they tell me it is the head gasket? Is there a way for them to test to see if it is the head gasket or whether it is the inlet manifold gaskets?

 

[Nikkie]

Garage called last night and said it was the thermostat and it would cost $200 all in. Just wondered if there was anything I should ask when I pick the car up? I'm just slightly worried it might not be the actual problem

 

[Brett_jjj]

If a holden dealership have fixed it, they guarantee their work for 12 months I think it is, so if theres more problems with it overheating again, take it to any holden dealership and get them to fix it again for free. I think that if the engine has done over 150,000 km, theres a 90% chance it'll have leaking/weeping inlet manifold gaskets, its just so common for these maifold gaskets to leak on these engines once they get a few K's up..

 

[Shebang]

Nikkie any update on if they fixed it? I have a very similar issue and am interested to know.

 

[Bigjonhed]

I"ve just read your post regarding VT overheating and loosing coolant. I have a VZ one tonner V6 which is doing the same thing its loosing about a litrer and a half after a 90 km trip and after sitting over night I have to add about two litres before driving to work . I'd like to put my finger on what may be trouble is before I
take it to the mechanics. It does not get hot and there's no water on the floor after sitting also no water in the oil