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StienbargerR · Joined: 28 Oct 2005 Posts: 1362 Location: Richmond, IN

Just finished up my rebuild today! However, I do have a few problems.

The oil pressure is a little lower than I thought it should be after a rebuild, it is just one bar when idling warmed up.

The temperature once the car has been driven for a bit (not hard at all) is on the middle line. Is this normal? I'm thinking that these two problems are linked together.

Also, do I need to do something with the cooling system? Like bleed out the air or something? I was thinking maybe I am unaware of a procedure which is important there. I did put new water/coolant in and I've got a new water pump installed and a few new hose as well as a new t-stat. I was thinking maybe it is not cooling the engine properly and causing the low oil pressure.

It seems the engine is a bit noisier than it was before. It sounds kind of like the belt, but it is more audible than I think is normal.

Also, the acceleration seems a bit soggier than before. It runs quite fine though. Could this be a timing issue?

I hope this all makes sense, so my mind isn't quite as sharp as normal-there may be a few mistakes.

Thanks,
Ryan
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1978 924 NA
-250lb lowering springs, Euro Pistons

968rz · Joined: 21 Aug 2006 Posts: 537 Location: S. E. Wisconsin

For the coolant fill, you should have a bleed plug in the top hose (i know my 79 does) I fill it up then run it until I see water then plug it up and run it a bit more until I'm sure the air is out and put on the rad cap. In my auto tech days I would let the fan cycle 1 or 2 times to make sure all is working. For the temp gauge, watch it while your bleeding the system; could be you have a better connection now and its reading right (fans should come on about 3/4 and off about 1/2-yours may very)

The oil pressure I'm not sure of, the original 79 manual states at temp/ldle the gauge will read low (1-2bar) and the light may flicker but this is normal. Thats a "new" engine so a rebuild may act the same.

The "belt" noise may be just that, recheck the t-belt tension and alt/PS

Low power could be a timing thing, try bumping it up a bit and see, just don't let it detonate/ping.
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Rick
79 924 coupe Petrol Blue 3spd auto (wife's DD)
93 968 coupe Amazon Green 4spd Tip (my DD)

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

Did you replace the plastic elbow on the oil delivery tube on the cylinder head?

I don't care how good the old one looked. The plastic gets old and shrinks. Then, you will get an oil leak, and lose pressure.

And what about the oil filter? Are you using a German one, or a Jiffy Lube Special?

You did replace all of the bearings, with the correct size after you measured the journals, and checked the clearance on the new bearings, right?

StienbargerR · Joined: 28 Oct 2005 Posts: 1362 Location: Richmond, IN

Thanks, that is really helpful.

I did replace the plastic elbow, man it was a tight fit to get in there.

I replaced all of the bearings. I didn't check the bearing clearance :-/ However, all of the correct size bearings are in it for sure.
One thing though- for the oil filter I just got the Advanced auto parts zone filter. I figured I'm not going to have it in long.. Should I go and buy a better filter.

Thanks,
Ryan
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1978 924 NA
-250lb lowering springs, Euro Pistons

924RACR · Posted: Tue Jan 08, 2008 3:42 am Post subject:

That's reasonable oil pressure hot, with new bearings.
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

The temperature gauge reading is going to depend on which thermofan switch and which thermostat you installed. Half way reading on the temperature gauge is propably normal with the standard temperature rating parts.

How do you know you have the right bearing clearance if you didn't measure?

1Bar at idle would seem a little low to me, especially on a fresh rebuild. Both my 924s idle at closer 1.5-2.0 Bar at idle with over 300K miles on the 77, and close to 100K miles on the 81 (with Valvoline 20-50 dino oil). Of course the weight of the oil and the type of oil would make a difference. I forgot to ask you what you have in there.

StienbargerR · Joined: 28 Oct 2005 Posts: 1362 Location: Richmond, IN

Gohim-
Well, I think you may have a caught an error of mine. I experienced a little bit of bottom end noise today

I am going to take a closer look at it soon. I hope it isn't the rod bearings... ugh.

Ryan
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1978 924 NA
-250lb lowering springs, Euro Pistons

StienbargerR · Joined: 28 Oct 2005 Posts: 1362 Location: Richmond, IN

Just a quick update if there is anyone interested-

My friend's dad who is an SAE certified mechanic came to look at my car today. All of the racket was coming from the belts. The timing belt was over tensioned and it was much quieter once he got it to the correct tension. Now that I can hear the engine better I don't hear any bottom end noise at all..

It sounds more like the alternator belt is slipping.Also it is slightly misalligned. I guess the rebuilt alternator I bought doesn't have the correct amount of washers in between the fan and the pulley, so that's an easy fix!
Only bad thing is that there is alot of noise from the drive train.. Luckily I have a low mileage tranny to swap.

Ryan
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1978 924 NA
-250lb lowering springs, Euro Pistons