Oh yes we did.
In our quest to give the engine a clean bill of health before putting it back in the car, we are digging deep. Don’t want to miss something important.
How did we get here? “A noise” led to a timing chain/guide job, which led to “how about we change some gaskets while we’re at it?” And now, we’re coming dangerously close to a rebuild.
Does it need a rebuild? Probably not. We could just take care of the timing chain and be done with it. But this isn’t just a story about resurrecting a neglected car. This is going to be my brother’s daily driver, and he doesn’t want to have to pull the engine again for a LONG time. He’s in it for the long run.
We pulled the engine off of the transmission (its “oil pan”), and removed the timing cover. The timing cover gets sandwiched between the head and transmission, so popping the cover off scuffed the head gasket above a little. But that’s okay, because we’re already planning to replace the head gasket in the name of preventative maintenance anyway, and will put it back together in the correct order.
I was expecting to see some broken bits down in the oilpan/gearbox to explain the brief “shattering” noise I thought I heard. Here’s what we found:
Looks like... a chunk of cured paint? Red paint? Some of the smaller bits may be pieces of chain guide, and I think there are some chunks of gasket material too, but there certainly aren’t any chain links down here.
The chain was intact, but seemed to be stretched. We found a spec stating that the tensioner must not be extended more that 11mm. Lo and behold, it was extended about 10.5mm. I’m sure that some of that can be attributed to guide wear, but whatever. The chain and guides are all getting replaced anyway.
With the transmission disconnected, we took a quick peek at the bottom end. I took a second to see if I could wiggle any of the crank bearings. There was some play, which we will look into later using some Plastigauge. If this thing needs bearings, now’s the time.
Unable to mount it to my engine stand, we set it back down onto the gearbox. Continuing with disassembly, we pulled the head. Everything looked ok, but we did notice some deck scuffing underneath the head gasket, as if someone had cleaned it before putting a new gasket on. Interesting. Too bad we have no service history on the car. (Neither did the previous owner, apparently.)
Would be nice if we did. As near as we can figure, the gearbox appears to be from an earlier model. Because this one has a drain plug, which was allegedly phased out on 1991 and later models. Also, the transmission mount is a 1990/earlier style. This car is a ’91, so maybe someone replaced the transmission AND did some engine work. Who knows.