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Warped Cam Cover?

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

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RickHaleParker
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Re: Warped Cam Cover?

Post by RickHaleParker »

When you installed the Cam cover, did you Oil the bearing positions for the camshafts or did you leave it dry?
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1998 C70, B5234T3, 16T, AW50-42, Bosch Motronic 4.4, Special Edition package.
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tardcart
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Post by tardcart »

right, It can be line honed as it was at the factory, but the head would have to removed, the cover milled and then line honed and I doubt the result would be good. never scrap stuff until the job is done. (old cover)

tardcart
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Post by tardcart »

On the new head; dont bother to hand lap. it doesn't work and makes the contact larger where it meant to be just on the upper edge of the seat, the valves are cut one degree less than the seat . either get a valve job or use it as is.

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erikv11
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Post by erikv11 »

Bummer but it sounds like time for another complete head. And another round of at least new valve stem seals, have them do a valve job at the same time if you can stomach it etc.

Interesting that the cam covers can't be swapped but it is no problem at all to swap cams around, those are machined to the expected high tolerance.

Side note I will say that three times I have had the machine shop scrub the cam cover for me, because it is so much easier to re-assemble if I don't have to pick my way through that meticulous cleanup. I guess they are smart enough to scrub with a brush that shines it up without removing enough material to affect clearances.

OP in your first post you said head studs, did you use studs or bolts?
'95 854 T-5R, Motronic 4.4, 185k
'98 V70, T5 tune-injectors-turbo, LPT engine, 304k, daily driver
'06 S60 R, 197k
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jimmy57
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Post by jimmy57 »

The cover is matched to the head. During manufacture they put a matching number on both parts to assure the pieces can be matched if ever separated during various machining and cleaning steps. I know of many cases where covers were used from another head. The overhead oiling systems have an end that if left in oil filler hole (prior to having the louvered insert) would break the cover if the engine was turned over. The machining is usually consistent but if the cam bores in top are a couple thousandths offset from the bores in bottom then it will bind up the cam with the off set bores. The covers used to replace the broken tops were of severely overheated heads as the top is not harmed by the overheat. The techs bolted to cover down with a few bolts and no cams installed and checked the bore alignment. Most fit but on occasion they had to get another cover and try again when the bores were laterally misaligned. Before you give up, take the cover off and look for problems and then if nothing is found in any of the bores then put the cover on with no cams and see if the front and back cam bores on exhaust side have the ledge at meeting locations of upper and lower halves. Paint stripper gel from Home Depot painted on the sealant with a cheapy paint brush will let you get the anerobic off with little effort and little mess. do 6-8 inches at a time and let the remover sit 5 or more minutes. The stuff that bubbles up paint also bubbles up the sealer.

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