Drove it out of the garage last night. The motor mounts make a big difference. I think I need to tune the idle a bit; it still need a bit of gas pedal to keep running, but much better over all. Of course, I let it sit long enough that I had to re-prime the oil pump.
I think I have the right kind of oil filter on it, with the spring loaded oil retainer, but how many months can we expect those to work? Less than 2?
I think the next project is a battery tender, and then perhaps on the fender
Sorry for the lack of pics, it's getting to the point where it is dark a lot up here - I leave for work an hour before sunset and get home just at sunset. A black car on a black night just doesn't come out very well
Back into the garage! It's not maintaining oil pump prime and the factory method of priming is not working well for me this go round.
How much oil can a person squirt down the center hole?
Definitely thinking hard this weekend
I got a spare moment this weekend, and I know why it hasn't been holding oil pressure, and why the pump loses it's prime.
I don't know how clear the picture is; the OPRV is toward the fiddly-bit end of the scale. It is jammed open by something that looks like a chunk of o-ring.
Here's the chunks removed, with a 1" socket for scale
I don't recall replacing any o-rings or dropping anything into the oil system. They're pretty soft, so probably they wouldn't hurt anything beyond gumming up tiny oil galleys. I'm not really sure how to do remediation for crap in the oil system without something approaching a rebuild, so I guess I'll put it back together and see if I get oil pressure. Then maybe do a couple oil changes and see if I can clear things out.
While I'm commenting here - priming the oil pump via the OPRV hole is really easy, compared to the factory method.
I pulled the OPRV, set up a mityvac with a catch can and fitted an end to the OPRV hole. The hole is pretty big, so I didn't have a tip the right size. I used blue tac to make a ring around the mityvac tip and that worked pretty well (once I remembered to set the mityvac from blow to suck...)
/edit accidentally a word
Could that be black RTV gasket maker and not an O ring?
A friend had that happen with some gasket maker and it clogged his turbo feed lines.
In reply to crankwalk :
There's a possibility. I did do the rear cam tower gasket, and I used ultra black on that. I could see there being some squeeze out, since it's such a pita to get everything lined up on the first try
Yep, that did it! Clearing junk out of the oprv brought my oil pressure back!
Here’s my vacuum seal setup
Still running on on two cylinders, but I think it’s the spark. I swapped the plugs around and it still ran the same, but the clean plugs stayed clean, so I don’t think they were firing. Or perhaps the dirty plugs are too carbon fouled. I'll try gapping and cleaning them
I cleaned the plugs and fiddled with the gaps a bit. I also taped up some of the vacuum hoses under the intake.
I think I have it running on all 4 cylinders. Pretty smoky; I’m hoping it’s an air idle adjustment and not rings
Should be easy to tell if its fuel or rings.
That sounds like a valve issue. Does it sound uneven when you are cranking it? Smoke, pulsing, running rough... might have a burnt valve.
It's not the Porsche, but I picked up a new-to-me commuter car last week. I think it's pretty spiffy - I've been getting ~45mpg with a lot of idling to warm up in the cold weather
The weather is warming up here, so I took advantage of a sunny day with above freezing temperatures to idle the 944 outside for a bit. It was rough to start, and when the car warmed up it bogged a lot and threatened to quit. I let it cool down, fired it up and it started running a lot smoother. Much less lifter clatter, too.
video to follow
I think I'm down to one very noisy lifter and one sorta noisy lifter. The rest are humming away nicely.
The noisiest lifter ⬆️
I did notice that when I give it gas there is a significant lag between applying the pedal and anything happening. I'm guessing I have some tuning to do on the throttle body, since I resealed it and probably changed the idle settings.
I guess crankwalk wins the remote diagnosis prize - flat lifters make valve issues! :)
monknomo said:
I guess crankwalk wins the remote diagnosis prize - flat lifters make valve issues! :)
Whats your plan for now? are these hydraulic lifters?
In reply to crankwalk :
Yes, they are hydraulic lifters. My plan is to let it idle a little more and see if the sticky one can be persuaded to inflate. If that doesn't work, I'm debating either a quart of atf or some seafoam to the oil. If that doesn't work, I figure I'll pull the cam tower and put some new lifters in.
Yeah I would try replacing a quart of oil with marvel mystery oil and let the oil get really hot and thin to try and free it up. Can you drive it around the block? Hard to get good oil temp just idling.
In reply to crankwalk :
I'll have to wait for more snow to melt before I'll chance a drive around the block. We just had a 4" dump today, and I don't trust it to make it much farther than the end of my driveway on its bald, dry rotted tires in these conditions. You're right on the oil temp, though.
I'm about ready for spring to start in earnest. I just got out my bike on Sunday, looks like I'll have to wait a little more
No pictures, but I subbed 1 quart of oil for 1 quart of Marvel Mystery Oil and let it idle for a long time. It got quieter, but I'm definitely out a lifter. Long story short, I ordered a bunch of stuff from pelican.
Next up is:
- Pulling the cam tower
- Counting my bad lifters
- Buying 1 or more lifters
- Pulling the intake
- Replacing my vacuum hose rats nest
- Deleting the venturi tube
- Doing a timing belt job while I'm in there.
I was torn what kind of magic oil I should get to try out (atf? mmo? rislone?) but this came on the radio and sounded enough like 'magical mystery oil' that I was decided:
Marvel is good for thinning down a bit for these sort of things. Once you replace the lifter and there is no issue I wouldn't run it in the crankcase though. It won't hurt much but I only use it when i'm trying to fix or at least rule out issues like that.
Worked on the car this weekend.
I started with a todo list, and put it on the windshield so no one cleans it up for me
This is just to prove to myself that the engine was in one piece
I had help; can’t go it alone
I find these cameras useful for setting tdc . Getting up and looking for the mark is hard, let technology do some work
Yep, the cam mark and tdc line up
Fuel rail is removed
Intake is removed. Why did Porsche hide so many connections underneath it? It’s just mean
Well, here’s one vacuum leak
Knocked a couple items off the list. Need to get some more brushes to clean gunk off the inaccessible parts of the engine, while I have it exposed
Check the valve springs while you've got the cam tower off. You might have a broken one. Mine was the inner one which wasn't readily visible until I took them off. But you should be able to tell the difference between an intact inner valve spring and one that has folded in on itself.
See my build early on... End of page 3, beginning of page 4:
https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/1988-porsche-944-track-toy/105890/page4/
In reply to CrookedRacer :
That’s definitely something I’ll keep my eye on when I get that deep
While we're here, let's look at some pictures of valves
Got the cam tower off:
I have one squishy lifter (#3 exhaust valve, which is what sounded noisy when it was all together). The valve springs look ok, but I haven't looked at them closely yet
In reply to monknomo :
Having gotten as deep into this as I have, I'm struck by how much easier it'd be to work on if it were a pushrod motor. The space with the cam tower out! There's so much room for hose and wire cleanup now!
