ok,

problem:
3 rocker cover bolts are now snapped into the cylinder head, one has a snapped stud extractor tool !
have re-fitted all, awaiting some action, (loads of HYLOMAR!).
Have some theories, can I have some GOOD eductaed guess's or real experience.

TIME LINE:
1> originally removed bolts (they were really tight)
2> when refitting I torqued them all up, Now I possibly Over tignedten them but were all ok, ran engine up to get her hot, then tigten them again, switched engine off, done another check and one bolt snapped
3> car ran with no drippage at all for at least 1 month
4> today (with some help) we tried to remove the original bolt, but then snapped a stud extractor into the hole.
5> decided to leave dogs lie and put back together
6> on refitting old bolts (with a new torque wrnech set to 15lbs) seemed a problem , so turned down to 8lbs, snapped another one, then while hand tigteneging, stnapped the third

ok, theory is, that step 1 & step 2, had stressed/streched them , so now they were really weak, so questions (considerening there are 13 bolts, 9 long ones (£25 each, 4 small ones £5 each)

1> the bolts are Allen keyd, and are a weird shape ie not a not bolt, but contoured, going to do some manufacturing using standard bolts and collers etc.

2> was considering bolts from a breakers but, if these soft alloy bolts are stressed are they prone to snapping ?

3> HOW DO YALL tiugtened them up, with an allen key, hand tight ? or how

4> ANY OF YALL had similar problems ?

5> replacing the 4 short ones are not a problem , but if I have to shell out £25 quid for 9 !

6> going to drill out the old bolts carefully and if the thread strips (it looks like there are inserts) are they available, or dealer fit, other option is to fit a heli-coil, which cuts a thread inside the insert so the orginal bolts will fit.


ideas, suggestions, shoulder to cry on

((((((((((((((((((((((((


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there are no rocker covers? Im not sure that I would tighten bolts again after an engine is hot. Maybe after it cools down again. Probably not then. Might try some anti sieze compound on all bolts into an aluminum thread.. When you retap the holes for the thread repair devices make sure you tap slowly and plenty of tapping oil desigined for aluminum. You can easily bind up a tap in aluminum..

 

I think you guys call it "cam cover" ?

cheers for the other info

A

 

From what I've seen the capscrews are tight coming off even though they call for 15 ft lb. I use a long version allen head socket, good quality snapOn,
MAC etc. I did use a craftsman Allen wrench with a wrench as a cheater.
I don't understand why you retorqued her up more with the engine hot on a alunimum block, thats usually a no-no, you can risk stripping threads out and damaging the capscrews which is what has happened
The first initial torque is all they call for (15 ft lb.) at room temp.

In your case, I would remove all the remaining capscrews, pull the cam housing off, if you can't remove the remaining snapped bolts. That involves removing the timing belt also. Extract and replace ALL capscrews, check cyl head threads for damage, reinstall housing and draw the housing down finally torque to 15ft lb. starting from middle and working out in a circular pattern.

As for making new capscrews? Buy new ones, not worth the aggravation, any more problems you might encounter. Also the clearance issues with hex head capscrews, hence the allen head bolt design. You might find some grade 8 allen head capscrews of proper thread and length at a fastener supply warehouse. GOOD LUCK

 

Adrian,

A sharp metal chisel and some careful hammer work, and you can get the heads off those bolts pretty easy (I should know, I JUST did two of them myself). The cam cover bolts are actually pretty soft, which is what caused your problem in the first place. Once the bolt heads are off, you can remove the cam cover and then get at the remaining studs with a set of lockable jaw pliers (also referred to as "Vicegrips" here).

The other alternative would be to cut the heads off with a Dremel tool, but I don't like shooting sparks at the fuel lines... drilling is also a secondary option, in my opinion.

Don't despair, its really not that bad.

Regards,

 

Hy & sh,

ok, the capscrews (I think pet calls them cheesehead screws)

they have snapped at the thread level, so the hole is full of the snapped thread, therefore it is parallel with the cylinder head insert

see the drawing,

 

I checked one of my CD's with the eninge manuals on

the torques are 7.5 ft/lbs not 15, dont know where I got that from ??



Think that means hand tight !

wery wery wery pissed off

 

Yep, it's not much torque at all, I broke one before when someone told me 18ft/lbs. Luckily, it was the bolt that went into the chain tensioner and was super easy to get back out and didn't do any damage to the head.

 

I'm guesing I have a good feel for tightening. I torque the rotating assembly, crank bolt and head studs, but not really anything else. I did this with mom's car 2 years ago, no problems so far. I trust my judgment, but if there's any question, there's no question, I go straight to the books. Good Luck

 

Adrian,
We were talking about 2 different engines, by the drawing and I just noticed S2. 16 valver, right? Looking at your drawing, looks like those are the capscrews that hold down the bearing caps for the cams which I believe is 15 ft lb. There are 2 hollow bolts on the tensioner housing that are torqued to 7 ft lb. You indicated only 1 that was broken. Is there another bolt next to the 1 that is broken? If these screws are broken then they shouldn't be a problem to remove since they have no tension on them, although you may have to remove the bearing bridge caps to gain better access to remove the broken stud. Sometimes just a sharp ***** punch will slowly turn them out.

 

hy944,

yep s2, the CD I have for the 16v (6 volume .pdf files on cd) say's 8, haynes (8v says 16 !???).

There are 3 bolts broken, the ones with the arrows
bottom one is about the 2nd bolt in from the front
the middle one is the 3rd (I think) in between sparks 2 & 3
top one is the first bolt cloest to the front

 

I bought a Hazet torque wrench specifically for this job. Once you get the snapped bolts out, I suggest you use one when tightening them back to avoid them from snapping again.

 

Adrian

are these the bolts that hold the bearing caps down that hold the 2 camshafts? the center bolt I believe is for the bracket that holds the chain tensioner

 

I "think" the top and middle one might be ?
bottom one is head

not taken the head off simce last night

take the day off to do some other stuff like the brakes !!!!!!


btw,

I managed to bleed the brakes successfully. Now, all the pads look fine "with" the exception that the front pads (1 pad on each wheel "outer ones I think on both wheels) is a lott lower than the inner ones, is this normal, or do I got another problem

cheers

A

 

The brakes are the least of your probs because if your head bolts are snapping off then I wouldn't be driving it because of furthering damage to head assembly, ie, water leak, warping the head, oil leakage etc. if it hasn't already occurred. Torque on the 16V heads are angle torqued in three stages 15 ft lb. first stage then 60 deg rotation, then 90 deg rot final.

First off, your going to have to clarify what bolts are broken because of the different torques, this will also determine the severity of the tear down.
If they are head bolts (10 of them) they are located under the 2 camshafts, usually not accessable because the shafts get in the way and you can't get a socket on them.

there are camshaft bearing caps and bridge caps, 4 caps for each shaft (8 altogether) 1 bridge cap at the front and 1 in the back tieing the 2 shafts together. 2 bolts for each small cap and 4 bolts for the bridges.

Then there is the chain tensioner. each shaft has a sprocket that a chain ties together, that I believe has 2 bolts that hold it down. This tensioner is right behind cyl 2. You can tell the tensioner apart because it rides under the chain pushing up the chain (hence chain tensioner).

Now you should be able to tell what bolts are broken.

As for the brakes, 4 piston brakes, sometimes you do get a little uneven wear, just the severity but just check to see if the pistons retract by getting somebody to step on the pedal and see if they come out. Use a screwdriver and slip it between the rotor and pad and see if you can retract the pistons back into caliper. The rotor should turn freely with some lite scrubbing when the pedal is released.