Sailor Jerry

I recently picked up a 170K engine from a '96 NA to swap into my '97 (mine had a hole in the block from the PO) and I'm in the process of doing basic maintenance on it before I put it in the car. My plan is to do a basic service to include the timing belt, timing idler/tensioner pulleys, water pump, valve cover gasket, cam seals, front and rear crank seals, and give it a good cleaning. The bottom of the engine was filthy and covered in oil so I knew that the crank seal was a must. Yesterday I was removing the last few bits to get the timing belt job done and I got a good look at the oil pump for the first time. I've attached a pic for your viewing pleauree, but it appears that one someone tried and failed in attempting to replace the crank seal. It's obvioisly in bad shape, but there are numerous scratches on the face of the pump around the seal. I also found what appeared to be remnants of black RTV around the seal; as if someone couldn't get it out so they attempted a half-assed repair instead. I can't tell if the abnormalities around the perimeter of the seal are part of the casting or were caused by someone attempting to remove the seal. At this point I'm concerned about the sealing service.

Is the damage bad enough that I should replace the pump? If so, should I spring for a Boundary pump (this car is not a DD and will be used for autocross, track days, and the occasional twisty mountain road)? I'm not all that excited about pulling the pump and oil pan, but I'll do what I need to so tthat it doesn't leak when it's back together. Please let me know what you think. Thanks!

themonkeyman

While it is a **** poor job it should seal fine. The sealing surface is really the bore the seal sits in, not the edge/face that's marred on yours. That said, the crank keyway doesn't look the hottest.

Sailor Jerry

Here's another shot of the crank keyway. Does this need attention before I put everything back together?

HarryB

Did you actually replace the seal on not? If the bore is OK, I would not bother with the pump. Crank is ugly but it should not be a problem, the rest of the keyway seems fine to me.

Icedawg

Looks like you could ignore the keyway damage. But you should check the crank timing pulley for similar damage, and replace it, if it is damaged too.

There were lots of "loctite" fixes explored for the early B6 short nose crank. Use of loctite "liquid metal" for a keyway like yours was recommended.
The higher end loctite products are usually not at the standard autopart stores, but should be available at more specialty dealers. Here in Canada I would say Acklands-Grainger, but I don't know for other countries.

Here is a link to a nice compilation on how to repair partially damaged keyways, posted by Harry Sue in 2000. And the relevant text itself, posted below.
I don't believe you need to use loctite on the bolt, given it is so much longer , thicker, and designed better than that early short nose crank bolt.
https://www.miata.net/garage/hsue/crank/loctite_2.htm
H Sue says:
If when you dismantle the engine you find damage which is limited to the keyway as shown in Skip Cannon's article then here are the steps you should take:

1. As far as possible using a small file clean up the keyway damage, removing burrs etc. from the area where the pulley seats. Take care not to file the undamaged side - this will be your reference for correct alignment during re-assembly. If the pulley keyway is damaged then it is best to use a new one. Using emery tape (not to fine because a coarser surface works better with this repair method) linish the crankshaft to a smooth slip-fit.

2. Clean the bore of the pulley and mating shaft area very thoroughly using a cloth and solvent or methylated spirits and let dry for 5 minutes.

3. Without inserting the key, slide the pulley anto the crankshaft and determine the bore clearance - plastigauges are good for this.

4. Squeeze a little Loctite Quick Metal into the keyway and fit the key. Fill the damaged part of the crankshaft keyway with Quick Metal.

5. If the diametrical clearance is less than 0.2mm put a coating of Loctite 242 or Loctite 243 threadlocking compound around the shaft where the pulley seats. If the gap is greater than 0.2mm then coat the shaft with Loctite Quick Metal instead.

4. Re-assemble using a new key (make sure it is fitted in the right direction). Use a new bolt. Before inserting it put a couple of drops of the Loctite 242 or 243 on the threads and torque to specification. Remember to keep a clockwise pressure on the pulley during assembly to ensure correct alignment. Torque bolt to specification (80-87 foot pounds).

5. DO NOT START THE ENGINE FOR 24 HOURS.

Sailor Jerry

HarryB - I haven't replaced anything yet. I wanted to get some opinions on the condition of the oil pump and crank keyway damage caused by the PO before I got to work.

Thanks for the guidance guys. The timing pulley doesn't show any signs of damage and I replaced the pulley boss (beacuse I sheared the locating pin for the harmonic damper off, LOL) so I guess I'll go ahead and replace the crank seal and get it all put back together.

HarryB

Pull the seal and check the bore and the crank surface for scoring.

x_25

Keyway looks fine. If the nose is assembled right, they key isn't holding anything anyway. Just slather every mating surface on the crank nose in loctite 243 (medium, oil resistant blue) when you put it together abd it should be fine.

Turbomack

Is the key shown in your first pic the one that came out of it? That key clearly looks too small (in width) for the keyway unless there is an optical illusion.

Sailor Jerry

The key is not installed in those pics. I believe it's an optical illusion.