1999-2009 [Subscribe to Daily Digest] |
Job: Timing chain (TC) / Cam cover TC guide / Cam cover gasket / Head bolt replacement. -- Completed !
Thanks to all who have contributed to the BB on this. Leo referenced âLetâs Roll in a Timing Chain . .â, MI-Roger gave rationale for doing head bolt replacement slightly differently than the 2005 head bolt replacement TSB (that is, not all at once, but sequentially), SwedeCar gave a definitive reason (in 2005 post) on why NOT to lube OEM replacement head bolts (bolts pre-lubed to match torque instructions).
Now a synopsis of Why, What, How â describing mostly the items that I found different than what I read from Leoâs recent posts on TC and the âLetâs Roll . . . â document (not on this site):
Why: I had left our â99 2.3t SE sitting for several days. Started it up on a cold (ca. 32degr F) morning with hood open and heard noticeable TC rattle from the cam cover area â traced with stethoscope. Pulled the tensioner and found that it was at 13mm extension. Research on this BB made me aware that I should change at least the cam cover TC guide as well as TC. It also alerted me to head bolt issue (TSB) affecting my car. My â99 had no service history of that TSB ever being performed. The car was not leaking oil badly, but had some seepage from cam cover (and maybe TC end of head gasket?).
What: I decided to try a TC roll-in (I did one on a 9000 once). I ordered new head bolts, an IWIS master link chain, cam cover TC guide, cam cover gasket set, and seals for the TC tensioner. I purchased the same Harbor Freight chain tool I found referred to on the web, and I ground down one of the motorcycle diameter pins to use on the TC. I used a Dremel for grinding the rivet ends off of one link.
How: âLetâs Roll . . . â has a good description of the preliminary belt removal and prep. I did this with the tensioner in place, but at the fully retracted setting. I did not remove cams or sprockets. I did it solo and used a long bungee cord over a garage rafter to put constant tension on the old chain up and forward as I rolled it out. I turned engine to exactly TDC (twice to be sure) before starting. Used about 25 zip ties (maybe 30 ?) to always have at least one on each cam sprocket at all times. As soon as the rotation went about 2-3â a new zip tie went on, and the old one got clipped off. Helper bungee was attached to old chain with extra zip ties. Added new zip tie and moved bungee connection point every six inches to keep tension. The angle of the bungee was a little awkward and near the end of the old chain (not much wrap on the intake sprocket) the chain jumped one tooth (just on that sprocket). Because of constant tension on the chain and lot of wrap I was sure the chain had not jumped at the crank sprocket. With new chain in, but still attached to old, I loosened the tensioner a little and coaxed the new chain end forward to its proper place for joining to the other end of the new chain â joining via master link done ON the sprocket to hold chain in place. Then advanced it and placed towel underneath (between sprockets) to add the face plate and peen the rivets. I used the 2-hammers method, and I had to only lightly peen rivet ends to get the 3.4 mm diameter specified in WIS. I screwed the tensioner back in and THEN rotated the crank pulley two double turns (to TDC twice). Everything still lined up at TDC. On to the head bolts.
Regarding the head bolt replacement, I think that the car was overdue. I decided to do the 2 separate stages of torque in sequence after I checked the torque to tighten the bolts using 44lb-ft setting on the torque wrench â and virtually all of the bolts yielded a little before the click, or just past it. I would guess that if my car where an Aero with more boost and higher cylinder pressures I would have already purchased a new head gasket job. Only question now is how much time did I buy? Bolts 1, 2, 3, 4, 5, 6, 9, and 10 all came out nice and dry. Bolts 7 and 8 had oil in their holes. I cleaned them out well before putting in the new bolts, but the only way I can see oil getting into the holes is that oil from the head gasket leaked in. I suppose that this doesnât have to mean a total gasket failure, so for now Iâll keep an eye on it.
For the cam cover gasket I tried Permatex bronze sealant to hold it to the cover. But I let the cover sit for several days waiting for the head bolts, and when I went to put it on the head, the outer gasket fell off the sealant. I cleaned sealant off and I used zip ties to hold the gasket at all bolt holes. I slid the cover into place using my fingers on back side of cam cover to coax the outer gasket into the groove. I clipped the zip ties off in sequence, and the gasket laid down nice and flat. I might use zip ties again.
Would I roll in a chain again? Yes. The chain noise is totally gone, and the chain tensioner is minimally extended (about 5mm). Only question is what part the absolutely brittle cam cover TC guide played in the noise.
Thanks again to all who have posted on these items. I will post on how long we can go before we have to get a new head gasket.
Mark in Marine (MN)
â99 2.3t SE, 179K miles
posted by 74.47.46...
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