Cracked exhaust manifold

[sickpupppy]

Hi guys. Lola just had her annual health check which highlighted a crack in her manifold. Although not affecting emissions greatly and only an advisory I wondered if it is possible to plug it with chemical metal. Garage advised not changing it as bolts are liable to snap in the head and be a pain.
Could use it sorted as fuel consumption has gone through the roof all of a sudden.

Many thanks
Dan

 

[crossedmike]

could u not just wrap it in exaust heat tape to seal it and keep it hot

 

[sickpupppy]

Not sure. I imagined it being near the gasket end of the manifold or even the gasket itself.
I will have to have a proper look at it when I get a minute spare.
I was just thinking of that elusive quick fix lol

 

[crossedmike]

Not sure. I imagined it being near the gasket end of the manifold or even the gasket itself.
I will have to have a proper look at it when I get a minute spare.
I was just thinking of that elusive quick fix lol

lol but could it with stand the heat or not that would be my concern

 

[sickpupppy]

My point exactly. I've used it before on a bike exhaust. But much further down the system where the temp is a lot lower.
I am open to ideas though.

 

[crossedmike]

a tube of decent high temperature silicone sealant/instant gasket stuff (says it's OK for up to 500C on ebay and p[robably most motor factors but to be safe i would use something like this then maybe wrap the exaust to keep it sealed and then a second line of defence on the sealent so not open to weathering or road crud

 

[Cupra Kid]

I'd put money on an exhaust mani passing 500c

 

[crossedmike]

slap 2 layers on at 1000c lmao

 

[toonfiend]

Is it bolts or studs that hold it on? If its studs you should be ok gettin it off. I changed one on a 1989 Toyota MR2 last year, first time those nuts had been touched in 20 years! they were just blobs of rust. I drowned them in WD the day before and with the use of a breaker bar they came off no problem. However if its bolts I too would be a bit wary! Ive used chemical metal/liquid steel whatever you want to call it on loads of stuff, but never on such a high temp piece,cant see why it would be a problem though, it wont hurt to try.

 

[HoopDub]

weld it

 

[F2 Ed]

wondered if it is possible to plug it with chemical metal.

Dan

I've tried this so many times. Never works for more than a month

weld it

 

[HoopDub]

if its accessable then id weld it, ive done a couple, one on a 1.8t golf, did it off the car, and one on a corsa, on the car. cast is a bit of a git to weld, but if you get it hot enough and crank up the power on the welder it usually work for a good while

 

[sickpupppy]

Thanks guys.
Chemical metal holding well for now.
However the crack is very accessible so weld could be an option in time.

Dan

 

[sickpupppy]

hmmmm,
chemical metal failing slowly, good call guys lol.
spoke to an old welder today, he is apparently an expert at welding cast.
he says,
"the secret to welding cast is to not get it too hot, if you cannot hold your hand on it for more than 20 seconds its too hot, work small and tap with the hammer as you go, never try to seal more than an inch at a time as the heat will get too much. slow work but done properly can last for years"
proper old guys who by reputation knows exactly what he is doing (local council contractor for metal railings etc)
i am to pop up during the week to let him at it

many thanks for the thoughts, advice and chuckles guys
Dan