|
This is not a job for the average mechanic. This job requires a person who is part mechanic, part machinist, and very careful and fastidious.
The top section of the head has to come off & the cams have to come out. Once you get those out you will see that about 70% of the area of the top surface of the bottom head section are oil communication holes or openings for things to fall into. These will all have to be masked so that no chips of aluminum get into them. That's after you identify all of the problem holes in the bottom head section. In your case, where someboby has apparently been messing with those bolts, all bets are off, and you would reasonably need to qualify each of these blind threaded holes (there are about 46 of them). This would require measuring the minor diameter & qualifying the pitch diameter of each hole. It's a bit tedious, but its not rocket science. It requires a few pin gauges and a pitch diameter plug gauge (~$30 of these tools).
Once you identify the bad holes, these must be heli-coiled after the careful masking of the top of the bottom head section as cited before. The heli-coiling must be done very carefully as there really can't be any mistakes. This is a lot harder leaning over that engine compartment than doing it in a machine shop.
All this is in addition to the usual Volvo issues associated with working with the chemical gasket which requires the utmost in fastidiousness and care to do the job right.
While you're in there, you might want to replace the hydraulic lifter set at another $135 if the engine has 100k miles or more. You don't want to be going back in there later.
The good news is that the job can be done and should yield excellent results in the right hands. The bad news is that you should try not to wait too long before fixing it as the incomplete and assymetric contact force should be expected to allow warpage in the casting over time. If this became too much you would be looking at buying both the top & bottom head sections (the only way they are sold). This would get VERY expensive.
One last note. Since all of the threaded holes in the bottom head section are blind, the fact that you are seeing oil seeping out of those bolt holes means that the oil is seeping over the chemical gasket interface, i.e. the head top section is lifting to some extent. There is no way this is going to get fixed without taking that top head section off.
For the hardcore driveway mechanic/machinst, its a solid weekend job. I'd think that at ~$800 labor you could get about 10 hrs for an experienced dealer mechanic. That might do it. You also need some special tools to do the job that the dealer mechanic WILL have. They may want to charge you a bit more for the lifter set, but they might let you get it. The price I gave is a super-deal price on the Volvo part.
|
