cracked manifold

[weazgti]

oh the list of things i need to do to my ebay rip off golf.
this prob is really getting to me cos all the other things are relatively easy to fix but i know this one aint.
my exhaust manifold must be cracked cos as soon as i put my foot down i get gassed out and have to open the window before i pass out.i can not hear a blow at all and was just wondering how do i pin point where it is coming from?
i did bit of exhaust fitting in a garage when i was younger but never actually come across this problem(apart from inlet manifolds but that was a case of spraying white grease on it till the engine run differently)
any one got any suggestions please.

[Ben Lessani]

Surely its more likely to be the flexi on the downpipe?

Grab a piece of tissue paper and hold it at various points around the exhaust system - when it wiggles, you've found your leak.

[DarnPB]

Unfortunately you have a bit of a problem. The manifold is unlikely to be cracked as it is a substantial peice of struture. However, whether it is or ot is not, it needs to come off to look at the gaskets and replace them. This includes the gasket to the head and the lower gasket to the down pipe. Now the bolts that holds this little mother on are very difficult to get to with the engine, or at least the head in place. You may find it easier to lower the subframe complete with engine to expose the bolts. Either way, its a work up and I would allow a weekend for the work.
You would also have to allow for some of the studs that WILL break and will need replacing. I don't envy you the task.

[Reasty]

When my manifold cracked you could clearly see it just by looking at it,had a big crack right between two of the tubes,as said the problem is it's a nasty job to get off and studs will snap of,I would suggest you replace it with a four branch if the manifold is at fault,I got the Phirm to do mine on the 16v and 2 studs snapped off which meant time which also meant a hefty bill I think everything Including four branch was about £600 altho it was a while ago,so have a good look at your manifold before you do anything drastic,if it's cracked it will more than likey be onthe top and if it s you will cleary see it.

[Wayne]

I have seen a cracked manifold before, start it from cold and hold your hand near and see if you can feel a blow.

[Steve_B]

Surely you'd be able to hear if the manifold is cracked? I've had a blown gasket before which I thought was tappet noise at first.

[Diamond Hell]

A cracked manifold can make all manner of peculiar sounds, which will sound like anything else but a cracked manifold.  A leak of exhaust gas into the cabin isn't necessarily the manifold.  If it is you should check the various grommets etc on the firewall as this should be reasonably air-tight.

As people have said, use your hand of some material to try and locate the blow (or use your hand if you're a real man and the car's not hot).  My money would be on the manifold gaskets on the head.  These are held on with peened (locking) M8 nuts.  If people have replaced these with plain M8 nutes they will come loose quickly and you will have a blow back in no time.  Check for leaks on the gaskets and check that the nuts are funny-looking copper ones and that they have washers under them.

If the manifold is shot I have a spare one in Bristol.  PM me if you're interested.

[weazgti]

there is no really obvious noise but the smell is enough to make you open all windows.
have checked with paper around manifold but no signs of blowing,the only reason i thought it could be the manifold was because of the smell in the cabin but that smell has npw changed cos got home today and my heater matrix spewed out on the carpet.

bit of a change on the subject but just looked on the heater matrix guide on here and it mentions replacing the gasket around the pipes where it joins the bulkhead cos otherwise you will get engine fumes in the cabin.

Could this be the cause of the fumey smell?

[richard s]

on passat forum there is something about a curry type smell before heater matrix goes its something to do with the type of antifreeze used
maybe it was something along those lines that was giving off the smell

[weazgti]

definatly engine smell although i did notice the smell you mentioned when i got in my car then i noticed water on the mat.
And i didnt have heater bypass valve on,was wondering how long that would last!!!!!