Manifold Missing A Bolt, Two Others Loose...

[KrazyKong]

I noticed on the weekend when installing a new dump + front pipe I was missing the rearmost exhaust manifold bolt on my car. I was surprised to see this, but figured ok I'll track down a proper bolt.

Was under the car today and had a closer look. Surprising the two bolts nearest to the one I'm missing were so loose I could turn them with my fingers. Not really being prepared to deal with it, I tightened them as best I could with a fixed spanner.

Now I'm thinking rather than just finding a replacement for the missing bolt, I might be better off checking all the bolts on the manifold. So what's involved in this? Obviously all the pipes above have to go, but is it possible to check all the bolts without unbolting the turbo as well? I see there's an aluminium heat shield that covers the manifold as well.

Anyway, since I have no knowledge of experience for this part of the guy, am hoping someone where knows what's involved. Hopefulyl I don't have to take off too much of the car so that I can get to and check each bolt is nice and tight.

[R31Nismoid]

I presume you are talking about the exhaust manifold studs?

If so - Manifold off & replace them all at once.

It's a common item that needs replacement after 10years or so, especially if the exhaust has not been mounted properly putting stress on things @ whatever point.

[KrazyKong]

Nismoid, I'm not experienced enough to know if that's what you are referring to or not. It's the manifold that looks to be in two sections of 3 pipes on the exhaust side of the engine. The bolts go in pairs, one top and one at the bottom, actually it's more like a 45 degree angle that the bolts are on. I'll take a picture tomorrow to be safe and show you what I'm referring to.

Ah ok, so rather than just try and get a replacement bolt, or stud I should take them all off then. So this would require taking the turbo off and all the surrounding pipes etc. right?

[boostn0199]

Yeah thats the manifold you are talking about and yes to get to all the bolts you would need to take the turbo off, unless you are getting a real bad exhust leak then dont bother changing it until you have the turbo off or something because everything must come off.

[KrazyKong]

Yeah thats the manifold you are talking about and yes to get to all the bolts you would need to take the turbo off, unless you are getting a real bad exhust leak then dont bother changing it until you have the turbo off or something because everything must come off.

I can't hear a leak, so that hopefully has to be good news. I do see what looks like oil around that area, but it's highly likely it was from the rocker cover gaskets and thus has simply leaked down. I'm not planning on having the turbo out at any point, so this would be a huge job by the sounds of things.

Looking at a few pictures on the net

I can see the bolts/studs. I'm not just missing a nut, I'm missing the whole thing all together. I hope it just fell out vs snapped off. Will have to shine a light in there to see if it's snapped or not.

Ah crap, this isn't a job I really want to do, and it looks like it would take days. I don't have any tools for dealing with snapped studs and all that stuff.

Other than the extraction of snapped studs, I think I could handle the removal of everything. It looks fairly straightforward unless taking off the turbo with all the lines and other things is a nightmare.

Edited May 13, 2010 by KrazyKong

[JonnoHR31]

they always break, just leave them if its not leaking and make sure whatever ones you can get to are tight, but dont go trying to torque the shit out of them or you'll probably break them

[Victory]

Exhaust studs are a very common problem with RB's to the point where I have had them replaced on my GTR and GTS-T.

It involves disconnecting the exhaust, removing the turbo and then the manifold. Hopefully there will be some stud still sticking out so you can get a stud removing tool on them otherwise it involves drilling them out and using an "easy-out" to get it all out. When they are all out polish the mounting face and reinstall with a new gasket.

Either way it is something that you need to do and if you go to this much trouble then replace the entire set so you do not have to do it all over again when another one breaks.

[mattis96]

what is the stud size for the rb 25det? i assume the rb30 will be the same?

[KrazyKong]

Great I found another stud missing from the exhaust manifold. It's now missing the rear most and front most ones. Will have to have a proper crack and seeing if they are missing or snapped off, though it won't be this week however.

[Mister25t]

Great I found another stud missing from the exhaust manifold. It's now missing the rear most and front most ones. Will have to have a proper crack and seeing if they are missing or snapped off, though it won't be this week however.

I doubt they would have fallen out, the manifold expanding with heat cycles and cooling off would have stressed them and snapped them off, especially the end two. They also normally break at the radius of the shorter thread (the part inside the head) so there doesn't tend to be much left sticking out.

Sounds like the manifold is going to need a surface grind too. I'm guessing its a bit banana-ish.

Sorry I can't give you better news, if you are good with a drill you could get them out yourself but it may be a good idea to leave it to a pro.

Studs are M10x1.25 i think.

[perzn_34]

i have the same problme for the last 3 months .. car runs fine.. bit of a backfire but i cant hear and leaks..

should i go about fixing it or just leave it as im planning to sell the car in a couple of months??

[KrazyKong]

I doubt they would have fallen out, the manifold expanding with heat cycles and cooling off would have stressed them and snapped them off, especially the end two. They also normally break at the radius of the shorter thread (the part inside the head) so there doesn't tend to be much left sticking out.

Sounds like the manifold is going to need a surface grind too. I'm guessing its a bit banana-ish.

Sorry I can't give you better news, if you are good with a drill you could get them out yourself but it may be a good idea to leave it to a pro.

Studs are M10x1.25 i think.

Thanks for that info Rob. I'm not hearing any leaks or noises in that area. So is it possible I could just have snapped or missing bolts, and the manifold not be banana-ish? I don't know how much the easy out kits are, but it sounds like some serious tool expenditure for those as well as a 90° drill attachment.

The more work I do on the car, the more I discover things. Am so wanting things to be over and just drive, wash and smile basically.

[jjskyline79]

If you want to remove them diy then follow the link in my sig

If you hear a ticking noise its leaking as its the gasket flapping about and you will be loseing boost pressure if its leaking too.

Edited May 14, 2010 by jjskyline79

[perzn_34]

i really dont care about loosing boost as i have enuff... but it harm the engine tho? ive heard it makes the cylinders dry or something??

[jjskyline79]

You have enough boost lol ok

Simple answer is yes you will course more damage if you dont sort it out.

Question is why wouldnt you want to sort it out???

[perzn_34]

it seems a bit costy and i want to sell the car... howmuch would you guess it would cost?? the gasget it around the $100 mark the labour..??..

[Duncan]

It would be a full day's work for a workshop assuming you have a few missing bolts. Don't start the job yourself unless you are confident, snapped studs are hard to remove and your car would not be mobile.

btw I disagree with the post a couple above. Assuming the car is running smoothly and you are happy with how it is performing, it is not urgent. You won't get any "worse" damage from continuing to drive it....you will just slowly lose power as the leak gets worse.

[KrazyKong]

Well well. Learned something today as I was picking up a part for my car. A guy I met today tried screwing in a stud into both my back and front "missing" holes. In both of them the thread stuck and started to screw in!! So this could mean I am only missing studs rather than them being snapped off.

When a stud snaps in the exhaust manifold does it snap right at the point it's flush with the manifold, or can it snap way into the head?

Will try and get a camera in there to take a picture, but it might be tricky. If it turns out I'm only missing studs as opposed to having them broken, this might not be such an ordeal as I had feared.

Oh, and this is interesting. I was told of a method to help bet out a broken stud though it requires some welding equipment.

Step 1 is to weld a washer to the end of the broken stud. Step 2, weld a nut to the washer. Step 3, use a fixed spanner and out she comes. The person who told me this has actually used this method to get them out, but it only really worked since his neighbour was a welder. Anyway, some food for thought.

As far as driving it goes, currently I can't hear and manifold leaks. Powerwise I've only seen an increase with all the work I've done on my car lately. Still I will make an attempt at some point to take off the turbo, and have a real look at the exhaust manifold studs.

Edited May 15, 2010 by KrazyKong

[jjskyline79]

It would be a full day's work for a workshop assuming you have a few missing bolts. Don't start the job yourself unless you are confident, snapped studs are hard to remove and your car would not be mobile.

btw I disagree with the post a couple above. Assuming the car is running smoothly and you are happy with how it is performing, it is not urgent. You won't get any "worse" damage from continuing to drive it....you will just slowly lose power as the leak gets worse.

Agreed but its not best to leave it because it will eventually breach then if you continue to drive it and you dont at least course the manifold to warp like a banana then you would be lucky

Ps it cost me just under $300 to do it myself but i refused to pay the down right rip of cost for a Nissan parts/gaskets when there were far better and uprated parts for far far less

Edited May 16, 2010 by jjskyline79

[Duncan]

yeah good point...I meant no further engine damage or anything major....do doubt the longer you leave it the more stuffed the manifold is likely to be