VT 5.0L exhaust manifold cracked or gasket leak

[cliffo83]

I was just driving my VT 5.0L when I noticed some smoke coming from under the bonnet on drivers side, so I pulled over to inspect. There was still some minor smoke coming from the rocker cover gasket and exhaust manifold area, I couldn't quite tell???. Then the smoke stopped. I drove home without any smoke. Btw there are no warning lights showing, checked the engine and trans oil which were both fine. Upon a visual inspection of were the smoke was coming from around the rocker cover gasket exhaust manifold area, I noticed some old oil build up around that area, Which may be causing the smoke or might indicate a worn rocker cover gasket I'd think, But it could be exhaust manifold gasket also. Any idea's???
My neighbour is a mechanic, so I'll ask for his advice when he gets home from work.

 

[cliffo83]

I let the car idle for a bit, had a look and theres exhaust fumes coming from the rear of exhaust manifold. So either manifold is cracked or gasket needs replacing. Any guides on how to remove manifold or change manifold gasket on VT 5.0L's? I can't find any..

 

[Immortality]

It's probably a weeping rocker cover gasket. that's where I would start. Replace and clean and see what happens.

I was under the impression the exhaust manifolds were bolted directly to the head without a gasket from the factory. To do a exhaust manifold gasket you would want to loosen of the exhaust system flange bolts (where the exhaust system bolts to the exhaust manifold). Then remove the exhaust manifold bolts which should allow it to move far enough away from the head to get the gaskets in and then reverse the process. Another option instead of gaskets is to use some Maniseal.

 

[cliffo83]

Hey, thanks for the info....I'm pretty sure it's the exhaust manifold or gasket. Upon inspection earlier I noticed it takes a good 5 mins before it starts to leak and can see smoke or what seems to be exhaust fumes. But it wouldn't hurt to start with replacing rocker cover gasket first and go from there I guess. Cheers

 

[BlackVXGTS]

+1 for a leaking rocker cover gasket. You won't see smoke until the exhaust heats up enough to vaporise the oil leaking from the rocker cover. If the exhaust was the problem you would see a lot of black soot near the leak location. Unfortunately, the driver side rocker cover gasket is a PITA to remove and refit, especially the bolt near the firewall. Suggest you de-pressurise the fuel system and disconnect the two fuel lines to give a little more clearance and working room. You will need a special tool to disconnect the quick release fittings. If you don't have one you can purchase a tool set for less than $10 at Supercheap and other stores.

I would suggest that you purchase a set of rubber gaskets like the ones in the link below. The are better quality and easier to fit than other forms of gasket. You mount them directly on the cylinder head. There are built-in lugs that keep the gasket in place and correctly aligned, and then it's just a matter of dropping the the rocker cover in place, with the brake booster and ABS unit doing their best to get in the way (LOL). Don't fall for the cheap imitations that are also on eBay. I purchased a set of these recently since I had to replace the driver side gasket on my 383 VS Calais, and the passenger side on my wife's VS Clubsport.

http://www.ebay.com.au/itm/NEW-HOLD...817997?hash=item33cb38a04d:g:4P8AAOSw0vBUZYSs

 

[cliffo83]

Thanks mate, I'll change rocker cover gasket first...I'll have to settle for whatever rubber gaskets I can find at Supercheap or Repco. Need car going tomorrow and can't wait for an ebay delivery to arrive.

 

[gtrboyy]

Give it a wipe clean,nip it up with allen key as usually they come loose...enjoy the contortion work getting to back bolts.
Don't think I've ever replaced a set ever just reused them all.

Go for drive then check again if any leaks

The cast headers bolt straight on,no gasket or sealer...if exhaust leak usually be at pipe flange or come loose.

 

[cliffo83]

Give it a wipe clean,nip it up with allen key as usually they come loose...enjoy the contortion work getting to back bolts.
Don't think I've ever replaced a set ever just reused them all.

Go for drive then check again if any leaks

The cast headers bolt straight on,no gasket or sealer...if exhaust leak usually be at pipe flange or come loose.

I nipped the bolts up except the back one, I couldn't fit my hand in that small space. Went for a drive and Doesn't seem to be leaking anymore....

 

[gtrboyy]

It's a fun job...nearly as bad as laying on engine to change dissy cap/rotor button/leads/coil...luckily when done safe for a few years.

After clean make sure no oil left on leads either

 

[Brisbarnz]

Flathead screw driver with the right size tip works alright for nipping up the rear bolt.