Greetings, I had gasket replaced 3 years ago with a head over-haul. Doing the gasket now myself with new bolts. Is another trip to the machine shop advisable after 30K and 3 years? Are there any reported issues with bolts bottoming out after a 'skim' job? Previous job does not seem to be down tight enough with build up and blow over between #2 & #3; and #3 & #4. Bolt holes were pretty dirty, bolts were original, so maybe this was the issue. Any comments appreciated.

Did you run a tap to clean the threads in the cylinder head screw holes? What do you mean they ‘‘bottomed out’’?

The bolts never did 'bottom out'. I asked the question about bottoming out because I knew the head had been skimmed and I was unsure if it was an issue as I was trying to figure out why there was not sufficient clamping pressure.

Although there was not warpage in the head, there was a degree of 'brinelling' around the ports on the head and slight low spots between the ports. I used a wet stone with oil to even these out after cleaning.

I am pretty certain that the head was skimmed without the cam in. However, I am pretty certain that the head was bolted in with the cam in place. Journal mis-alignment is a factor to some degree I think.

In addition to combustion gas cross over between the cylinders, the intake side coolant passage on number 4 cylinder was migrating into the cylinder ring and introducing coolant into the number 4 cylinder. Solid deposits between the same coolant passage and bolt hole on the intake side of #4 cylinder makes it obvious there was not enough clamping pressure at this point. I wonder if the misaligned cam shaft contributes to this, as the cam is super strong iron compared to the soft aluminum head.

An excellent slide show regarding this issue of cam shafts interfering with sealing on a Volvo 230 engine is here: http://www.pbase.com/stealthfti/image/25088683

I thoroughly cleaned and chased all the bolt holes and used new bolts to make sure.

Hi,


If the head was surfaced, you should have no issues. ‘‘brinelling' around the ports on the head’’ I don’t understand. Didn’t you have the valves ground and the seats cut?

You really need to make sure the head is all the way on the block surface and not cocked BEFORE beginning the tightening sequence. The block has dowels which must fit into the head before it will make proper contact.


Goatman

just did this to my 940 and had the head resurfaced but head bolts did not bottom out even though I had a fair amount shaved away.the biggest risk in not replacing head bolts is that they break, and that was a little discouraging because extracting them took hours.

Thanks for all replies. The original gasket installed 3 years ago was a victor reinz. The more I look at the old gasket, it seems as though the proper torque was not applied. I recently installed a new gasket and that last 90 degrees is quite the pull. I used a meter and 90 degrees with the meter seems to go further than just eye-balling the angle of the breaker bar while one is pulling. So--I think the main issue will be resolved by proper torquing.

As an added incentive to do this job oneself, and not let it out to a generic garage, it should be noted that a lot of info on this brickboard is pretty specialized. Just a little trick like not installing new hushers until after the valve adjustment is done really makes a big difference. Three years ago, a valve job was done on the head, but now there is an issue of excess valve clearance on a few of the valves. I am doing that now. I think it will help things.

Also, the generic garage three years insisted on putting some sort of grease on the gasket even though I begged them not to. The entire bottom of the head was one big oil slick of goo. That goo just cannot be good for a good seal.

I say all this as appreciation for the good info on this site, and as a word of warning for those who entrust their machine to strangers who just want to get through it all as fast as possible.

Sorry to hear your "generic garage" did such a poor job installing the head.

Since the head was not torqued properly I would suggest double checking to make sure the head is flat before going to the trouble of installing the new gasket.

As someone stated make sure head is flat, block must be clean of all old gasket, residue, etc. On my car when I did this a year or 2 back the head was warped about 6 mils, again, make sure it's flat if previous shop did not do it. Many think you can just plop the head back on, but it engine overheated once, it's probably not dead nuts flat.

Also make sure bolt holes are clean, no old oil, coolant, etc down there. As stated, head bolts can be reused, do not re-torque as these are torque to yield bolts, i.e. tighten to specified torque and twist 'em another 90 degrees. Finally, buy new exhaust studs and replace so one or more don't break when you torque manifold up. Good luck.

I'm not an expert but something sounds amiss...

Head overhaul 30k miles ago, and you need another head gasket? A reworked head + gasket should go for a lot longer.

If the head job was torqued to spec then why the blow by between cylinders? Improper torque due to dirty thread holes maybe.

Warped head?
Did the shop who rebuilt your head check if the head was warped?
Did they not torque in the correct sequence and so warp the head on install?

I do know it is important to clean the threaded holes in the block before installing the head. A tool for this can be made by carving grooves into a head bolt (I forget the term for this process).

I would advise finding the problem of why the gasket blew before putting the head and new gasket back on. For sure try to check if either the head face or block face are flat.

Hopefully, one of the experts will chime in.

And spend the money on the OEM correct type hard style head gasket.

head gaskets jobs done properly ought to last 00's of 000's of miles with no comeback to the doer of the job.

clearly something went wrong.

i would look to the use of an inferior grade of head gasket before blaming the bolts or the torque specs which are straight forward.

in any event blame is pointless now since it must be redone.

use a good head gasket, reuse the bolts, ensure no liquid exists in the bolt holes in the block and clean everything well.

run a straight edge end to end side to side and diagonally across the head and measure for space. if under .005 you needn't resurface. it ought to be well under.

pay attention to the proper unbolt and rebolt headbolt pattern and adhere to it.

• Volvo says head bolts can be used up to 5 times

• Head bolt re-torquing is not mentioned


--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

I'm no HG expert, but I remember seeing mention of:

1) Use new head bolts every time you remove them
2) Re-torque the bolts after 50 (or 500?) miles of driving.

If you think the bolts bottomed out, and that's the cause of the problems... I just don't think that's likely. If they took enough off the head or block to cause that problem, my intuition says you'd have much more serious problems.

Do you have any guess as to why it's leaking?

Good luck!