welch plugs

[freeway29]

HI all got a vs v6 3.8 ecotec engine and noticed it was leaking a bit of coolant and coming from behind the bellhousing, so my guess is the welch plugs is there any there and if so how many and any other seals that could leak coolant thanks.

[Krisp]

there is 4 welch plugs, check for intake manifold leaks from above

[Jacko84]

i thought mine was leaking down the back too put a pressure checker on it leaked outa the thermostat housing down the valley and dripped down the bellhousing. leason learnt allways have a good look around the whole engine bay

[freeway29]

ok thanks so is there any welch plugs at the back of the motor where the trans covers it.

[Pub247]

yes there is

[freeway29]

just wanted to know as some one said there was also a metal plate type of thing with seal, and talking about have to drain the oil and that does that sound right and is there 1 or 2 plugs at the back.

[wamboin23]

could also be leaking heater core - drain pipe is just above transmission, pretty common for them to leak

[nathanVY]

pretty sure there's no welch plugs at the back of the engine only the rear main seal, which does leak coolant on these engines. common problem, mine was really bad, had to have the whole rear seal / aluminum plate replaced.

[freeway29]

ok must be what hes talking about then as he said to do the lot going to cost $350, also hate to seem dumb here but where's the intake manifold as ill check that first is it under the engine cover thats held on by 4 nuts or not thanks lol

[nathanVY]

$350 sounds a bit cheap, the plate it-self should cost $150. make sure he does it properly! see my thread, early pages theres pics of when I did mine.

[freeway29]

looked at it thanks but been to him before and hes good, by the way where;s the intakeas i asked is it undthe the engine cover thats held on with the 4 nuts or not thanks.

[hako]

There is a welch plug at the back of the block and to replace it you must remove the gearbox/trans....most people just add some 'stop leak'...the other plugs are also difficult to change. Do a search on "commodore welch plugs".

[cander24]

As mentioned, you need to determine exactly where it is coming from first. Give everything a thorough degrease and then try and trace where its coming from. If its dripping from the bellhousing area i'd say there's a good chance its your rear main seal. On the back of the block there is an alloy plate which holds your rear main crank oil seal but this plate also seals against the block with coolant passages. As the alloy slowly deteriorates and corrodes with age this seal begins to fail and drip coolant as you've mentioned. Gearbox has to come out to replace this.