Should I pull the head?

[Hombrey]

Hi guys. I've got a TD42 with some snapped exhaust head studs right at the back about 4 have gone. Now got an exhaust manifold leak where the studs are missing plus its turbod and I've got what appears to be an inlet leak plus don;t know when the injectors were done last (near 300k). So thinking about pulling the head to get all these things done. Is that a no no on Diesels if they are running well. Does pulling it kick off a raft of problems or are they fine? Any opinions from experince would be cool. Also any other things I should do if its off?

[coxsy]

as i can see it, pulling the head off is a reasonable option, to fix the studs, if access is bad , a new head gasket is not going to raise the compression at all.

[corosafari]

Depends where studs are broken , if flush with head will need to drill out and may need to remove head for this.
You dont need to remove head to do injectors. If not sure when these were done it is good idea to do this . The springs in these are known to loose tension lowering injection pressure causing poor combustion. So replace springs and nozzles. This will improve combustion efficiency, power, economy and longevity of engine so money well spent.
Use suitable exhaust manifold gaskets to suit turbo.
good luck

[Hombrey]

Hmm ok thanks guys. Yes they are flush and at the back of the head. In fact the very back two holding the rear of the manifold is where its started leaking, plus the one in front of that and two others. When I fitted the turbo I tried to get at them with a drill but thought I was gonna probably do more harm than good given the angle I could get at them. So plenty of cement and bolted up tight but thought it was probably temporary, and it is. Given these are a pushrod engine hopefully the head off and on should not be too bad. Cheers.

[darinz]

Don't pull the head. I had the very back stud break off on mine and it broke of flush.
The easiest way to get them out is to weld a big nut onto the stud. The heat will loosen them and then they will just wind out.
What you need is a big not, about a 12mm. Drill it with about a 3/4 drill about half way through so you can get the mig inside the nut to weld the stud to it. It may take a bit to build the stud up but once you have it is by far the easiest way to get stud out. (If you have the right tools that is)

[Hombrey]

Hmm tempting. Guess the trick is don;t weld nut and stud to head . Might just have a go as need to strip turbo etc off anyway so worth a shot. Cheers.

[darinz]

The head is cast so takes a lot more heat to weld so you should be OK. I managed to do it to a VG30 (yes all Nissans have this problem) and that is ali head and it worked fine.

Also run a tap up the threads before fitting new studs. I'd suggest doing them all at the same time.

[Hombrey]

Ahh right good info. Thanks. Yes replaced the ones I could A year ago when fitting the turbo but the snapped ones I just could not get to so thought I'd pack in maniseal and see how long it lasted.

[TD power]

they will come out mate just weld a nut to them if they dont come out just drown them in frezze spary on the studs it srinks the steel they sould come out good luck make sure u use heeps of copper cote when u put it back togeta