944 Engine Refresh Pt1
This car came to me with 163,000 miles but seemed to run pretty well. I was aware of several little problems. One of these was how the engine had several oil leaks. The previous owner reported some oil usage but I was pretty sure that much more oil was being lost to leakage than to burning.
My early looks at the engine also showed there to be no water in the oil or oil in the water. There was slight evidence of “chocolate milk” under the oil filler cap and in the overflow bottle, which some say means there has been water in the oil. Later I decided this was just an amazing accumulation of dirt. All of the inside of the engine was dirty.
Also, in looking for the source of the oil leaks I found that the plugs at the rear of each of the balance shafts were not sealing well at all. They were so loose, I think I could have easily pried them out.
I studied on how I might fix the oil leaks, and learned that many before me have removed the balance shaft housings and even the oil pan while the engine remained installed in the car. But the more I looked at fixing these oil leaks, the more I dreaded doing serious engine work while lying under the car and in the tight constraints of the engine bay. Despite my goal to control costs, I grudgingly accepted that the engine would need to come out to get proper resealing.
This turned out to be a good decision as I found a few other things that needed attention. With the engine out, I got a good look at exactly where the oil leaks were coming from. First up was the oil separator. The lower seal was badly damaged, perhaps by an overheat event (see below).
Below is a picture of the seals, taken from the oil fill separator, notice how the one is scalded and visibly damaged. My photography is getting better, huh?
The oil seals at the rear of the balance shafts were not visibly damaged but were much smaller than was needed to make for a good seal. I'm guessing they had shrunk over the years.
The small leak at the 9:00 o'clock position (from the crank) turned out to be a real problem, but I didn't know it till the engine was re-installed and first being restarted.
And last there were a couple of oil pan leaks.
One note here on the timing belts: there is a lot of discussion concerning need for timing/balancer belts to be precisely tensioned. I'm not convinced that there is anything special about these belts. The previous owner tells me that haven't been touched during his ownership (which is about 80,000 miles). I plan to replace the belts along with a couple of the rollers that are worn.
White dust found in the water passages - doesn't appear to have done any harm but interesting.
Uh oh! See anything different in number 3? ChaChing!!! The broken ring (below) came out of that cylinder, I wonder if a little bit of blow-by would contribute to the oil leaks? Hmmmm.
Bearings seem OK, will replace them though. Rings and bearings - about $250.
About an hour apiece to clean these up. Will reuse them.
I knew I had heard a small exhaust leak, here it is. At first I thought I could have this welded but my welding skills are about even with my photography so decided to look for a replacement instead. Found a pair on Ebay for 47$, I went away from conventional hotrodder wisdom here and went with the cast iron instead of tubular steel. The cast iron is heavy, but oh so strong.
I tried to save a few bucks on cleaning parts, what you see above and a few trips to the car wash are all I used (the head and crank were hot tanked). Have to be really careful to not leave any steel fibers behind (almost missed one in the oil pump). Also coating on cylinders and pistons is very delicate (soft bristle brush only). The Westley's is great for rubber pieces.