Rebuild the engine or look for a tested used one?

[uvachief]

I am running into more serious problems on the 86 944 NA manual. I just dropped a ton on it doing a front engine reseal and a load of other work. Expected the car to run like new when I got it back. Didn't last 500 miles before it started having issues again. Idle started acting up and then it started to idle so low, it would choke out. Like it was choking on its own oil. I replaced the fuel pressure regulator and damper thinking it was causing the idle issues. When it didn't fix the problem, I went back to the original suspect which is the air oil separator tube and seals. Turns out the entire tube is cracked and the hose that leads off the a/o separator split and blew apart. The idle control valve is full of new oil. Asked for a compression leak down test to be performed. Basically, one of the 4 came back near original specs. The other 3 valves showed a loss of compression of about 15-20% from original specs. I think the correct valve was 160 and the others were in the low 120s but I will have to find the paperwork.

My question is rather simple. I've dumped a ridiculous amount of money in this car already. At what point do I cut bait with it? Is it better to rebuild the existing engine or look for a good tested used engine and do a remove and replace? I've got more than 3x invested in the car than it is worth at this stage. Has respray paint job but that's already started to flake and chip. I've removed and installed loads of new parts. Radiator, battery and tray, front engine reseal, lower balance shaft and oil cooler resealed, fuel lines, brake lines, regulator, damper, refurbished all brakes, replaced the hatch, interior is in real good shape now but cloth seats and your typical cracked dash, timing belt with new water pump, tensioners, rollers, etc. Replaced dead ac compressor with remanufactured one, new drier, etc. Fixed clutch. New exhaust system front to back. Dash lights all replaced and upgraded. Bought a set of 16" phone dials off an 86 951 and refurbished them with new tires as well. Oh and a new passenger side control arm.

I just don't know what to do at this stage. It seems like the more I delve into the engine block and make repairs, the more problems I find. I am so frustrated with the car right now.

[krystar]

find your local pelican mechanic and have em remove the head and replace some valves.


do a leakdown test first. if leakdown test fails, buy a tested used engine.

[Cocacolakidd]

If time is not a problem I would tear it down and do a complete rebuild. That way you know all is good to go. With the leak down test it shows that it needs rings and or valves minimum - while you are in there do the whole thing is what I would do.

Looks like such a beautiful car not to have every thing just right.

[carlege]

If you want to get out while your ahead put it up for sale. if you want a fun car and dont mind going through it, dive into it and take your time and enjoy yourself.

Concerning buying a complete engine: Unless the engine is running and you see it and hear it then i wouldnt believe the engine is in good shape. You might be buying an expensive boat anchor/ paper weight.

[John_AZ]

Nasty!

Did you have help in selecting your car? A PPI maybe?

carlege is correct on the engine.

Keep the car and buy a 2nd 944. With 2 you can pick and choose the good and the bad and sell the rest to your neighbor with a 16 year old son.

You want to drive a 944 and not "enjoy" it on your laying on your back.

Now you know what to look for and what to avoid.

Get a PPI on your next purchase.

GL
John

[kfanazini]

I would take a step back and get away from it for awhile. You are too upset to make a decision now.

[honerboys]

i agree with kfanazini - park it for a while and let yourself calm down about it - i'm assuming this is not your main ride - these cars can get under your skin in more ways than one - my son and i have been working on the 85 for 6 months trying to get it on the road - we wound up buying another one (an 83) just to swap it's engine into the 85 so i feel your pain - it now runs and we're getting ready for paint - so that would be my choice - find a car with a good working engine and swap it - test it (compression , leak down) - that way you could enjoy driving the car again and maybe remember why you bought it in the first place - it's a beautiful car - keep in the back of your mind that it's a used engine and you will probably need to replace it someday - also you could slowly start rebuilding your current engine so when and if the replacement goes you have a fresh one to put in - good luck

[John_AZ]

None of the Above-^1
John

[uvachief]

Originally Posted by John_AZ

Nasty!

Did you have help in selecting your car? A PPI maybe?

carlege is correct on the engine.

Keep the car and buy a 2nd 944. With 2 you can pick and choose the good and the bad and sell the rest to your neighbor with a 16 year old son.

You want to drive a 944 and not "enjoy" it on your laying on your back.

Now you know what to look for and what to avoid.

Get a PPI on your next purchase.

GL
John

I had a PPI. The engine passed is which annoys me. I should have relied more on the autocheck report. However, I ignored all the really bad warning signs. I bought it from a mechanic who drives a 86 944 NA. While he had done quite a lot to the exterior mechanicals (exhaust, remove and replace transmission, brakes, mini-service with plugs, distributor cap, etc.), he told me upfront that he had not gone inside the engine. I didn't know then that i should have asked for a compression test. The car had basically sat for almost 10 years after a major transmission issue and an odometer problem. She literally had not been on the road for more than a test drive in 9 years when I bought her. She began leaking oil like crazy as soon as she was regularly on the road again. Also, due to the extended period of time that she sat, so much had just seized, perished or rotted rot off the car. Every valve, gasket and seals needs replacing on this car due to sitting. However, I beginning to suspect that someone burnt a valve or two at the time they trashed the transmission. I had looked for about 4 months in 2010 and I really didn't see much else out there for $5,000 or less. If they had a good mechanical history, the inside was trashed as well as the exterior. If they looked pretty or had been repainted, they had no mechanical history or large gaps. I took it back a few times to the mechanic I bought it from and he worked on it but it was still leaking oil terribly the last time I got it back from him so I took to another mechanic who specializes in older Porsches and particular 944s and 911s. Every time the phone rings from this new mechanic, I dread answering it. I can pull and replace parts that are easily accessible but I've never rebuilt an engine (well a 57' chevy but we did that during an extended lunch break in high school - took only 1.5 hours). I've got your basic mechanic's tools but I don't have a lift, engine hoist, real air compressor, or things like that. I wouldn't mine learning on a parts car but I have no where to put it unless I rent a garage in the sticks which is becoming more and more of what I am thinking of doing.

[John_AZ]

uvachief,

HondaDustR documented an engine rebuild in his garage and it is one of the most complete.

Project 924 S engine replacement

If you plan to keep the car, I think getting a replacement engine would be the quickest way to get the car on the road and not have to rent a garage.

You have the ambition and tools to do an engine swap in your garage or driveway. If you drop the engine and install a "good" engine from the bottom you can get by with minimal tools. (The same way Porsche factory did it). Basic tools. Bloody hands.

GL
John

[v2rocket_aka944]

Rebuild the current motor.

That said, no matter how nice the car is or how well maintained it is there will be a point where your maintenance dollars exceed the car's value.

Take a second to think. Is the fun you get driving the car worth taking a loss if you ever sold it?

I am into my car 13x what I paid for it. I have spent $35 today for some switches and lightbulbs. I am going to put another $1000 or so into it soon for paint, and I haven't decided what to do for the dash yet. Since my car has been crashed before it is nearly worthless in terms of resale.

But it's 100% worth it.

[Rasta Monsta]

Pull it out. Pull the head, get a valve job. Assess the bores. Decide from there whether to use another bottom end with better bores, or use yours. On whichever bottom end you end up using, install new rod bearings and a crank scraper. Reseal motor, reinstall.

*Above approach seems to have worked on my race motor!


rasta

P.S. Did not vote. . .poll needs "Rasta approach."

[John_AZ]

Originally Posted by uvachief

I can pull and replace parts that are easily accessible but I've never rebuilt an engine (well a 57' chevy but we did that during an extended lunch break in high school - took only 1.5 hours).

I've got your basic mechanic's tools but I don't have a lift, engine hoist, real air compressor, or things like that.

I wouldn't mine learning on a parts car but I have no where to put it unless I rent a garage in the sticks which is becoming more and more of what I am thinking of doing.

I must have missed the part where uvachief had a twin with additional skills, tools and garage. Not to add the dimension of time to finish the rebuild.

John

[alfadoc]

Given that you have no real workspace, only basic tools and are relying on a mechanic, my recommendation would be an engine swap. I would try to find a complete, running car that is appropriate to part out. Swap as many of the new parts you've already bought onto the replacement engine. See if maybe the mechanic will take the remainder of the parts car as partial payment. If you can find a place to store it for now, hang onto the old engine. If your work space situation changes, put it on an engine stand and do exploratory surgery on it at your leisure.

If you ever think of buying another 944, particularly if you are spending real money for a car that's supposed to be right, take me with you. I'm only two hours away; I can always use an excuse to drive to Richmond.

[uvachief]

Originally Posted by John_AZ

I must have missed the part where uvachief had a twin with additional skills, tools and garage. Not to add the dimension of time to finish the rebuild.

John

The 57 engine was no bigger than a desktop computer and monitor. Our chemistry teacher use to take it apart and clean the whole thing from 3 to 5 p.m. about every six months. You could stand on each side of the engine in the engine bay. There was hardly anything to it other than a block, some valves and pistons. Wish today's engines were as easily accessible. Weren't the Porsches really designed for easy drop and replacement?

[uvachief]

That Bosch J-tronic fuel injection is plain bizarre to me. I don't understand it. I also don't understand the whole oil combustion recycling thing with this engine. There is only so much of it I understand and feel comfortable working on. Hell doing the regulator and damper scared me because I was so worried about damaging the fuel rail. And of course, I stripped the bracket nut on the regulator and ended up spraying fuel all over the engine. Luckily, I didn't set it on fire. The engine is just plain intimidating to me. If I had a real spare garage and could toy with a parts car, it would be worth learning it inside and out. However, with a wife and 3 kids under 4, there is ZERO time for that learning curve. I can only do simple parts replacements at this stage of my life.

[John_AZ]

Originally Posted by John_AZ

uvachief,

HondaDustR documented an engine rebuild in his garage and it is one of the most complete.

Project 924 S engine replacement

If you plan to keep the car, I think getting a replacement engine would be the quickest way to get the car on the road and not have to rent a garage.

You have the ambition and tools to do an engine swap in your garage or driveway. If you drop the engine and install a "good" engine from the bottom you can get by with minimal tools. (The same way Porsche factory did it). Basic tools. Bloody hands.

GL
John

Originally Posted by John_AZ

I must have missed the part where uvachief had a twin with additional skills, tools and garage. Not to add the dimension of time to finish the rebuild.

John

uvachief,

My comment was to support your decision.

I posted the engine rebuild done by HondaDustR as an example of difficulty.

I understand how your family obligations will focus your choice.

GL
John

[uvachief]

Here is a new one. Major loss of compression in 3 of the 4 cylinders generally means scored cylinders right? Bent or broken valve/ring right? How about just huge carbon build up that somehow avoided scaring the cylinders? Its rebuildable! Best news I have had in weeks. Still needs a ring job but that's a far cry from a complete rebuild from the bottom up.

[carlege]

i dont think you need a ring job..... maybe the valves are bad on the cylinder head.

[johnkoawood]

Didn't vote, not gunna, UVA, is the car at your house, or the mechanics?

If doing rings, and without history on the rest of the engine, check the thrust bearing for wear.. if ANY wear is detected the block needs to come out..

Replace the main bearings, and finish the FULL rebuild.. you will be better off in the long run!

ALSO make sure once the pistons are out the block is checked for roundness and taper... either one could cause the low compression, both CAN be repaired, however I hesitate to tell you the cost of it! (My 951 motor had zero taper, but was at the FSM limit for out of round.. it is now waiting to be reassembled after being repaired to perfect bores!)

Also sounds to me like you need to find some localish friends... I can say I have wrenched on cars from VA beach to Baltimore... Mosley is more in land that I typically go, but hey I am always up for a weekend trip to dive in and help out!