Bugger. Cylinder head problems.

Just when it was all going so well.....

Yesterday was spent removing the intake and exhaust manifolds, due to a blowing exhaust manifold gasket.

This morning was spent flushing all the gunk out of the intake manifold, whilst this afternoon was spent re-fitting everything.

The Haynes book of lies had sugested torqing the exhaust manifold studs / bolts / nuts up to 33 lb/ft. With this low number in mind I only did them up finger tight followed by 1/4 turn with the ratchet.

The first stud torqued up ok.

The second stud went loose before I got to 33 lb/ft. I solved this by turning the stud around so that the longer thread went into the head, (these studs have a gap about 1/3rd of the way down, before another thread starts).

The third stud is actually a bolt. This went 'loose' well before 33 lb/ft.

The forth stud again went 'loose' well before 33 lb/ft.

This is as far as I have got as I don't want to do any more damage. I have quadruple checked that I am reading the right figures for the torque settings, and quadruple checked that the torque wrench is set correctly. The old shared intake / exhaust manifold gasket failed in exactly the same place that these studs have gone loose. Coincidence???

So what are my options here for a novice driveway mechanic? Apply thread lock and hope for the best? Tap and die slightly larger holes and hope that I can get slightly larger bolts / studs? Add a box of matches and a gallon of petrol?

In advance, many thanks. :thumbup:


PS; it is a Discovery 300tdi.

Right, just took one of the bolts out, followed by a small coil of aluminium from the head and tried some threadlock.

It's made bugger all differance. it wont even torque up to a pathetic 10 lb/ft.

I have also replaced one of the old studs with a new one. This fecker wont even go more than half way into the head before it locks solid.

I've fecked it up haven't I? ****.

had this **** years ago on a v8 undone the studs/bolts and out came yer silly coil of alli,cobbled mine up with sum stuff made by loctite.was like a resin,cant remember the number it was either:doh: i know they used to use it on BMW Vanos camshafts to stick the plastic bungs into the ends of um, but all i did was bang it up the thread oles and put the studs in till they were about ta slip the threads.left it over nite and tightened them up sweet as a nut.
instant thread

oil dripper said:

had this **** years ago on a v8 undone the studs/bolts and out came yer silly coil of alli,cobbled mine up with sum stuff made by loctite.was like a resin,cant remember the number it was either:doh: i know they used to use it on BMW Vanos camshafts to stick the plastic bungs into the ends of um, but all i did was bang it up the thread oles and put the studs in till they were about ta slip the threads.left it over nite and tightened them up sweet as a nut.
instant thread

Click to expand...

Cheers.

I have done a quick search and founf the following products. If I list them do you think you might know which one is needed?

Ok, cant copy and paste from their site. I'll post a link. See bottom of page 4 and top of page 5. Cheers.

Loctite - Henkel

best way without resorting to bodges is to helicoil the head. do a search on google and you will find a kit for it. you just drill the hole out and retap it bigger, the screw a steel insert in to bring your thread down to the original size
summat like this www.buckandryan.co.uk/product.php/site/froogle/sn/DRP44067

gegs88 said:

best way without resorting to bodges is to helicoil the head. do a search on google and you will find a kit for it. you just drill the hole out and retap it bigger, the screw a steel insert in to bring your thread down to the original size
summat like this www.buckandryan.co.uk/product.php/site/froogle/sn/DRP44067

Click to expand...

With a kit like that, could i just tap into the existing holes, or like you suggest, would I have to remove the head and drill the fecker out, re-boring it if you like?

The Green Oval - Home. Free manuals to download.
Studs for 300TDI inlet & exhaust manifold are less than 10ftlbs so you've overdone it a bit

Timecert or helicoil

Disco Moneypit said:

With a kit like that, could i just tap into the existing holes, or like you suggest, would I have to remove the head and drill the fecker out, re-boring it if you like?

Click to expand...

if ya can get your self a 90 degree adaptor for your drill then it would be a piece o **** to just open up the hole then you retap it oversized, then you screw the helicoil in and it brings it back down to the proper size. cracking bit o kit and at you will be doing the job correctly