GTV exhaust manifold gaskets

Started by poohbah, December 17, 2016, 07:06:56 PM

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poohbah

I guess I knew it was too good to last - just ticked over a year with no dramas of note on the GTV. Went on a long drive two weekends ago, but got stuck in inexplicable congestion at 3pm on a Sunday (30min to travel 2km) on way home, after which the car sounded like a tractor (though it wasn't running hot, still pulled and revved fine).

Looking at it up close, it appears that the exhaust manifold gasket on cylinder No3 maybe leaking (I can see crappy carbon buildup all round it).

I'm a bit surprised, given I had the manifolds replaced a year ago. Am I wrong to think its unusual, or is it the sort of thing that can go anytime?

Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

poohbah

Good tip sportiva, I'll check the nuts.
Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

poohbah

I've identified the problem, and it is as simple as it is bizarre.  After wrestling the heat shielding out (what a pain that was), I was able to get a good view of both manifolds.

The two bolts which fasten the 1- 4 manifold to the exhaust downpipe seem to have undone themselves and done a runner. No wonder it's making a racket.

Question I have now is - any useful tips on how to insert and tighten two replacement bolts? I don't have axle stands or a lift, so haven't got access from beneath, but it seems impossible to get to from above, mainly because the manifolds themselves get in the darn way.

Is there a trick to gaining access from above? Or am I just going to have to get some axle stands and (assuming I can get the bolts in and nuts on) find a friend to hold while I tighten?



Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

aggie57

Quote from: poohbah on December 18, 2016, 08:36:40 PM
I've identified the problem, and it is as simple as it is bizarre.  After wrestling the heat shielding out (what a pain that was), I was able to get a good view of both manifolds.

The two bolts which fasten the 1- 4 manifold to the exhaust downpipe seem to have undone themselves and done a runner. No wonder it's making a racket.

Question I have now is - any useful tips on how to insert and tighten two replacement bolts? I don't have axle stands or a lift, so haven't got access from beneath, but it seems impossible to get to from above, mainly because the manifolds themselves get in the darn way.

Is there a trick to gaining access from above? Or am I just going to have to get some axle stands and (assuming I can get the bolts in and nuts on) find a friend to hold while I tighten?

Nope, you're going to have to get access from below. 
Alister
14 Alfa's since 1977. 
Currently 1973 GTV 2000, 2020 911 C2S MT, 2021 Mercedes GLE350, 2023 Polestar 2 LRDM
Gone......far too many to list

poohbah

Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

Duk

Can you build a stack of planks to drive the car onto?
Even jack the car up and put planks or bricks under the left front wheel?
Obviously anything you do must be solid and the car totally sure footed.

Using some ancient memory, I'm thinking I use to do the nuts for the secondary pipes from above and used a crows foot spanner to do so................ But that was a long time ago.
The Daily: Jumped Up Taxi (BF F6 Typhoon). Oh the torque! ;)
The Slightly More Imediate Project: Supercharged Toyota MR2.
The Long Standing Conundrum: 1990 75 V6 (Potenziata)............. What to do, what to do???

poohbah

Cheers Duk. I have got a set of ramps, so can at least get front off ground. Will see if I can get enough space under car using them, and try to do do it over Xmas.

I assume there is a gasket that fits between manifold and downpipe?
Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

Duk

Yes there's a gasket between the parts.
If it's still there it's probably a bit eroded from the gasses squeezing out the gap. Some exhaust sealant on both faces of the gasket could give it a new lease on life.
The Daily: Jumped Up Taxi (BF F6 Typhoon). Oh the torque! ;)
The Slightly More Imediate Project: Supercharged Toyota MR2.
The Long Standing Conundrum: 1990 75 V6 (Potenziata)............. What to do, what to do???

poohbah

Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

GTVeloce

Lie on your back under the car with a 13mm socket on a 200mm extension bar and try not to get anything into your eyes! Depending on the type of bolt used, you may need a second person to hold the bolt head from the engine bay. And put copper grease on the threads so they come of easily again later!

poohbah

Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

poohbah

Cheers guys for all the tips, lots of good advice.
Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

poohbah

Also, what is the correct size bolt?
Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

poohbah

Update.

Yes you can replace the flange gasket, nuts and bolts on your own without having to get under the car.

"All" it took was about two hours, lots of swearing, a selection of different length socket extensions, and some extreme dexterity...

Of course I only had to replace the rearmost flange gasket and bolts. God help me if I had to replace them on the front manifold.
Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)

poohbah

Maybe. More the need for triple jointed wrists. And fair to say I left a fair bit of skin on the manifold...
Now:    2002 156 GTA
            1981 GTV
Before: 1999 156 V6 Q-auto
            2001 156 V6 (sadly cremated)