Manifold gasket leaking = boost leak?

[l1ttle_d3vil]

The gasket between my turbo and manifold is leaking and/or the bolts keep coming loose.

Only seems to reach about 10, maybe 12psi now rather than 15psi.

Is this likely to be because of the exhaust leak, and is it likely to do any damage if I drive it like this or just loss of power?

And slightly off topic, any ideas on how to prevent the nuts from coming loose?

cheers

[Dell'Orto]

Would make sense to lose some boost pressure if the turbine isnt getting the full whack of gas...though depends how big the leak is I guess.
Lock wire would be the best way, otherwise you can get those ovalised lock nuts (name escapes me right now)

[Garreth27]

Had the same problem on my starlet so I loctite the shit out of each bolt and so far none has come loose, YET.

[Crucible]

Would make sense to lose some boost pressure if the turbine isnt getting the full whack of gas...though depends how big the leak is I guess.
Lock wire would be the best way, otherwise you can get those ovalised lock nuts (name escapes me right now)

+1

Had a small leak @ waste gate on mine and it affected spool up considerably. Spring washers behind flat washers work well too. Dellorto's suggestion would prob be a better way to go.

Fastening supply places usually have a really good selection of locknuts etc..

[l1ttle_d3vil]

Would make sense to lose some boost pressure if the turbine isnt getting the full whack of gas...though depends how big the leak is I guess.

Big enough to feel it pumping out at idle, and hear the difference in tone

Will check out what bolt fastners I can find. I have tried allsorts of spring washer (separate and mounted on nuts) but as soon as they heat up they go completely flat.

One of them is a PITA to get to as well and to tighten it properly basically have to pull the turbo + manifold off the car so hopefully I can get a permanent solution!

[ee904age]

Use Nordlock washers on them, they are a two piece washer with serrations on each half to bit into the nut/mounting surface and ridges in between the two halves that work against eachother so in effect the nut has to get tighter before it'll loosen off. Should do the trick.

[Distrb]

i use these on my turbo manfold. appear to work well

http://www.fun.co.jp/english/products/unut01.html

[Mr Ree]

What sort of gasket do you have? If its a fibre type, I would replace it with a stainless steel type, as the former always leak eventually as they cant cope with the prolonged heat of a turbo as well.

[RedMist]

Use Nordlock washers on them, they are a two piece washer with serrations on each half to bit into the nut/mounting surface and ridges in between the two halves that work against eachother so in effect the nut has to get tighter before it'll loosen off. Should do the trick.

Problem with Nordlocks and high temp is they fuse the two halves of the nordlock together. Good point is the serrations also fuse into the manifold which prevents them from slipping.

[XSVWGN]

Sorry for the thread hijack but i have removed my manifold and turbo and found the same thing. I had a steel gasket in there and it wasnt that flash. Bazda mentioned getting the surfaces milled so they were both flat and even. I have found it hardish to find a replacement steel gasket

Matt

[QikStarlie]

should get away with running no gasket, if you get both the turbo and manifold flanges milled flat. otherwise ive found single layer stainless gaskets the best, but still need both surfaces to be pretty good.

[evil_si]

Sorry for the thread hijack but i have removed my manifold and turbo and found the same thing. I had a steel gasket in there and it wasnt that flash. Bazda mentioned getting the surfaces milled so they were both flat and even. I have found it hardish to find a replacement steel gasket

Matt

Yea get both faces milled or surface ground flat,
Ill have a look may have a spare sinle layer stainless t3 twin scroll gasket some were.
If not a lot of heavy diesels use them cat, cummins, john deere, but wandering on in doesnt usualy work, most parts smackers want a model, serial number blah blah blah otherwise unless they are familiar with them its to hard

[XSVWGN]

The gasket i currently have doesnt really match up with the ports on the turbo. There is around a 2mm over lap on each end and that has just got a large build up of exhaust soot so i presume that will be restricting flow slightly too

Matt

[l1ttle_d3vil]

What sort of gasket do you have? If its a fibre type, I would replace it with a stainless steel type, as the former always leak eventually as they cant cope with the prolonged heat of a turbo as well.

Gasket isn't all that flash either so won't help with the leak. It is just the fibre type, tried to get a stainless one every time I've had the turbo off and just given up and put the original one back on, as the bolts come loose anyway

Finally found a stainless one on TM, then when it turned up it was for a T3 instead... will have to have another look, stainless one on the dump pipe flange is still going strong so that's definitely the way to go.

Will also check out some of these nuts and washers etc, hopefully get this fixed properly now...

Cheers
-Matt

[AE86fan]

I had the same problem and it took forever to find the right solution. In the end this is what I did.

1. Make sure the manifold and turbo mate together without the bolts binding, my T2 bolt pattern on the manifold was a little off so I filed a little from the turbo bolt holes, this gave a bit of space for expansion.

2. Get a good quality gasket. There is an outfit in New Plymouth that make gaskets, they made me a high temp gasket (unknown material) that was about 4mm thick, it had a little give in it and takes up any slight differences in the flange surfaces.

3. I tried all sorts of nuts and in the end got factory toyota exhaust manifold nuts that I drilled and lock-wired.

4. Make sure your turbo and downpipe are supported with some sort of brace, I modified the factory AE86 exhaust brace that bolts onto the bell housing.

Its worth fixing right, as soon as mine started leaking the first few times there was a noticable drop in power not to mention the risk of damaging something from the hot exhaust gases.....good luck.