Newbie Frustration S70 GLT Engine Overheated CLASSIC LMS Topic is solved

[Ozark Lee]

The only rub on replacing the engine is that the VIN 56 B5254T engine is somewhat scarce.

If the cylinders are damaged, which it is sounding less and less like they are, then just replacing the engine is really the only reasonable option. To fix an engine with ring damage that scored the cylinder walls would require boring all of the cylinders and then replacing all of the pistons and rings with oversized parts. It would cost thousands of dollars to rebuild the bottom end and I can't come up with a scenario where that makes any sense for a low pressure turbo engine. The only way I could justify that is if I was building a 450HP+ monster high pressure turbo.

The plug and play engines that are a no brainer to install are limited to the '99 and 2000 5254T engines though. The '99 and 2000 engines are actually a bit different internally (hydraulic vs solid lifters) but they bolt up exactly the same. You can use engines from later model cars but they require some minor modifications. The later versions have CVVT on both cams but you can just leave the intake CVVT unplugged and forget about it. I think there are some other small differences as well but from what I have read they are easily dealt with.

The pre '99 5254T doesn't have CVVT at all and it really won't work.

...Lee

[rspi]

Hopefully the rings freed up overnight.

I have no idea where you are getting this from? "Rings freeing up?" Why do you think rings need freed up? If the engine is turning, they are not stuck or locked.

When the crank timing is set, it is NOT TDC. Please try to get that out of your mind. These engines are timed by marks, not TDC.

At any rate, when I put a head back on, I ALWAYS wet the cylinders before I try to start the car. I need that extra compression to get it started. So I wet it and crank it for about 30 seconds. No issues after that.

Questions... does the engine have solid or hydraulic lifters? Did you pull the cam sprockets off of the cams when you pulled the head?

[denraden03]

@ rspi: I understand what you are saying about valve timing. As per what I have read on this forum and gleaned from other individuals, this is what I understood: And maybe it is all wrong.
When the crank gear is lined up between the two notches on the gear, it brings #1 cylinder to TDC. However, when the cams are locked in place with the camshaft locking tool the CVVT spring tension turns the cam gear back to the rest position which is about 3 teeth off to the firewall side. When installing the belt you will have to turn the exhaust camshaft gear( not the camshaft) clockwise to align the marks on the camshaft gear and the notch on the belt cover. OR is all of the above BS. Also the engine has solid lifters and no, I did not remove the cam sprockets.
What I meant by 'stuck rings' is that when you have a "overheating" issue, there is the possibility (not fact) of the rings being stuck closed during cool down due to varnish deposits Also since the car was working perfectly prior to the overheating issue, its just totally abnormal to lose compression on all of my cylinders. As of this point in time when I do the leak down test the air pressure is not going to the sump, but rather from cylinder to cylinder.
Please enlighten me on how the timing belt is supposed to be installed

[abscate]

I'm not sure you did the preload if the CVVT correctly. If you read that thread you will know about this, but it's different than the 1998 and earlier procedure.

[Ozark Lee]

If you didn't remove the sprockets it is very easy to set the CVVT preload but it won't change the compression numbers. Since you didn't remove the sprockets all you do is line up the timing marks on the sprockets and the cover and put the belt on. Next rotate the engine by hand, clockwise, two revolutions back to the marks. From there continue clockwise an additional 90 degrees. After you advance the 90 degrees, go back counterclockwise to the marks again and remove the timing belt off of the camshafts. Thread the belt back on and, as you go across the exhaust sprocket, reset the timing mark on the exhaust camshaft sprocket to line up with the mark on the cover.

Tighten the tensioner and give it a couple more revolutions by hand and recheck the marks. You will likely also need to touch up the tensioner to assure that the indicator is in the window.

All of your compression numbers are so low that they really can't believed. That isn't terribly uncommon unless you pony up for a Snap On or some other really high quality compression gauge. What is Germain, and you have confirmed it with your pressure test, is the differences cylinder to cylinder and that in and of its self says there is a real problem.

The timing marks on a whiteblock Volvo do not correspond with #1 TDC but it is in that general neighborhood.

...Lee

[denraden03]

Let me see if I am understanding this correctly:
Prior to removing the timing belt, you are supposed to:
Line up and mark the camshafts and crankshaft gear.
In my case I have two notches on the crank gear so I align it with the valley between the two notches.
I aligned the camshaft sprockets to the notches on the Timing cover.
Release tensioner.
When I remove the belt, the exhaust camshaft sprocket with the CVVT walks back counterclockwise with the CVVT spring tension
Since I have the camshaft locking tool in place, I just turn the exhaust camshaft gear clockwise the realign the timing mark.
Is this wrong?
I looked at the video on this site and did it exactly as shown.
My issue is not timing. It is low compression after machining and reinstalling the head because of the overheating episode
I am now assuming that the engine block deck is also warped, hence the low compression.
I have tried all of the recommendations given on the forum and no positive results.

[denraden03]

@LEE: I also thought of that. I borrowed two different compression testers and the results were the same.
So, my next step is the spend the necessary and pull the head again to check the block deck for warpage.

[precopster]

RSPI is correct; the crank mark is not cylinder 1 TDC but is VERY close. The cylinder is actually depressed by around 1.5mm at crank mark.

Regardless if you setup the timing as per your explanation I see no problem with cam timing.

The leaking cylinders are more of a worry right now. How much block preparation did you do? Did you sand the old gasket off or were you very gentle by using gasket stripper multiple times and use a soft scraper to remove the old gasket? Was ALL the old gasket removed? If you were a little brutal on the block these could be your leakage points.

Was the block cleaned with acetone/white spirits prior to head replacement?

How was it torqued? Did you do 2 torque stages then 135 degrees of rotation of bolts? Did you lubricate and clean the threads in the block and ensure there was no liquid in them? Did you lubricate under the bolt heads with assembly grease?

[denraden03]

Actually, I did notice that #1 piston was not all the way up with the crank mark lined up. It was pretty close though. Yes I gently cleaned the gook off the block, there was no gasket pieces stuck to the block. And yes I torqued the head down in the proper sequence. See my previous posts. I did lubricate the threads of the head bolts. At this point I honestly believe that the deck is warped so I am going to remove the head and check the deck. If the head was badly machined,(possibility) I will have to locate another head.

[denraden03]

SOMETHING IS REALLY WRONG. HERE IS MY QUANDARY. NEED SOME ADVICE BEFORE I TEAR THIS THING APART.ENGINE STILL DOES NOT START
Every time I check my engine compression the numbers change. taking the advice from members, I put oil in the cylinders and cranked the engine over to lube the walls. That seemed to help some but the numbers are not quite where it should be. When I did the wet test a while ago the numbers went up significantly,(averaged 160 psi) so I suspected I had a problem with the rings. However, I did three different compression readings over 3 days and these are the readings, using 2 different compression testers. All done on a cold engine, since it never started.
Day 1: Cyl 1 - 135; Cyl 2 - 128; Cyl 3 - 120; Cyl 4 - 100; Cyl 5 - 120
Day 2: Cyl 1 - 100; Cyl 2 -120; Cyl 3 - 95; Cyl 4 - 90; Cyl 5 -110
Day 3; Cyl 1 -110; Cyl 2 - 110; Cyl 3 - 90; Cyl 4 - 80; Cyl 5 - 100

I have built many different types of engines in the past and this is the first time I have seen compression variations like this, but this is also my first time working on a Volvo engine
Yesterday, I had some help so I did another Leak Test. I would assume that if all is well, the air pressure should hold in each individual cylinder, if the piston is at TDC and both valves closed. ( I did the same test on a Chevy 350 motor I have and the air pressure holds).Well, that is not the case. Lets take # 1 cylinder for example in my case and then apply it to all my other cylinders. I bring it to TDC, both valves closed and air escapes thru the rings into the sump and back up thru #5. If I apply air it does not leak thru an adjacent cylinder which would suggest that the cyl head gasket is not sealing properly. I can hear it going thru the sump if I put my ear to the oil filler cap. No air thru the exhaust pipe or intake manifold which tells me the valves are sealing properly. A mechanic who works on foreign cars including Volvos told me that that would be the case if my rings were not sealing properly, because that is the path the air would take.
Any thoughts on the above??