So, I've been getting ready to do the headgasket on my dad's 1998 S90, and have a few questions. I've read the 7XX/9XX FAQ on this, but am still wondering a few things. First, Why do I HAVE to get new head bolts? On my trusty B230F, I can reuse them a few times. Also, for this cam pusher tool, I'm thinking I'll just fabricate something, as I've done for my B230F engine valve springs. Something can always be fabricated for far less than the dealer prices. Is this a brutally terrible project? I've done an awful lot of car repair, but am wondering what other advice any of you folks would have. thanks a lot,

Nate Gundy
--
'86 240DL sedan, 260K miles, M46, K cam, 25/21mm sways, 260 front and wagon rear springs; http://valvespringcompressor.weblogs.us/

If you don't mind my asking, how many miles on this car and how did the old gasket fail? Thanks. Paul

The car has just around 100,621 miles on it. The problem is that it has low compression on the #6 cylinder due to a bad valve. In order to fix the valve, we have to take the head off. So the gasket itself is probably fine, but the valve definitely isn't.

Nate Gundy
--
'86 240DL sedan, 260K miles, M46, K cam, 25/21mm sways, 260 front and wagon rear springs; http://valvespringcompressor.weblogs.us/

The bolts are "angle tightened", after getting them all snug with a torque wrench, to induce some initial stretch and "spring" in the clamping action. This is needed because the aluminum expands and contracts more with temperature than steel/iron. You really need to use new bolts and then "stretch" them the proper amount when assembling the head.

A copy of the factory manual for the mechanicals of this engine will be worth every cent of the approximately $30 it costs for this project. (If you don't already have it.)

I've seen several home made cam clamps following the operating concepts of the factory ones. One set was made using large, 5/8" dia threaded rod with the end turned and taped to fit the spark plug hole. I'm making some using 3/8" threaded rod with one end screwed into canabolized and taped spark plug housings. Some steel flat stock with holes will form the bridge pieces.

If you very carefully mark the cam to the pulley before you take things apart you should be able to get it together well enough. If desired you can always take it to the dealer for a final cam setting with the tool later.

Just some of my planning for changing my cams from the 180 HP versions to the 200 HP versions.
--
'96 965 with 16' wheels at 114K. Had '85 745 Turbo Diesel for 200K.

Thanks for all of the info. I will get the head bolts then. I'll figure something out when I get in there for the cam clamps. I'll look into the factory manual. thanks again,

Nate Gundy
--
'86 240DL sedan, 260K miles, M46, K cam, 25/21mm sways, 260 front and wagon rear springs; http://valvespringcompressor.weblogs.us/

If I am correct, this is an extremely complicated rebuild. These engines are not B230Fs, but a newer style engine that reguires special tools and expertise. I don't even think there is a head gasket on this engine, but rather some sort of special sealant. Be careful.

yes, this is a complicated rebuild. However, there is a headgasket, as it is sitting in the room I am in right now. The special sealant is for another gasket. I am always careful, but thanks for the advice. THe more I've learned about cars, the more I've realized that there is a way to do everything on a car, and, although this engine is FAR more complex than my trusty B230F, there is a way to do it, and it will be a fun learning experience. thanks again,

Nate Gundy
--
'86 240DL sedan, 260K miles, M46, K cam, 25/21mm sways, 260 front and wagon rear springs; http://valvespringcompressor.weblogs.us/

while i drove bmw's(aka Big Money Waster and Break My Wallet)it was strongly recommended that the head bolts be replaced because of stretch.it just seems cheap insurance for the involved job your doing.
--
83 242 DL -129k, 92-965-195k, 94-965-203k, 84-242 GLT-Gone, but not forgotten,83-245GLT-1'st one (the 1'st 3 currently on the road)

Your comments regardins BMW's did not go unnoticed! Is your experience with older model years or recent. The most recent F.O.R. ratings listed the BMW as above average, well above Volvos.
--
John Shatzer, '97 V90 @ 105K