96 850 Turbo Wagon Mechanic's Challenge

[FlipIt]

For the past four days I've been reworking the main wiring harness that comes from the engine ECU and the transmission ECU. As shown in the photo below the plastic bellows is not fitted together (red arrows) and a breakout wiring branch has no loom to protect it (yellow arrow).

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The lower section protective sheath is also not properly fitted.

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I ended up removing the serpentine belt, loosening the power steering pump, removing both ECUs and their enclosure in order to fix everything. The serpentine belt tensioner requires a 3/4 inch square drive to rotate it. Since I don't have one I cut a short section of 3/4x3/4x1/8 inch aluminum angle stock, inserted it into the tensioner and rotated it with a 12 Crescent wrench. If I buy another Volvo I'll purchase a 3/4 inch drive.

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The underside of the ECU enclosure was a rats nest of wiring that needed rerouting to fit within the rigid plastic sheath. I finished reworking it and now have everything back in place.

Also for the past four days I've been adding Sea Foam thru the spark plug openings to soak the piston rings. Here are the before (slightly warm engine) and after (cold engine) results.

# Befr Aftr
1 125 130
2 138 146
3 142 160
4 153 163
5 117 162

The minimum specified compression for a warm engine is 156 psi. So now cylinders 3, 4 and 5 meet it when cold. I've decided to work on my leaks while continuing Sea Foam treatment of cylinders 1 and 2. I doubt that I'll need to pull the engine and replace the rings. I assume that the compression will continue to improve with Sea Foam soaking and running the engine.

[FlipIt]

Today I started the engine and let it run for about twenty minutes at idle. I selected all possible transmission gear select positions to make sure the gears engaged.

Using a length of hose to listen with I isolated the major exhaust leak to between the head and the manifold in the area of exhaust port #5. There is also a very small leak between the manifold and the turbo.

I also isolated my engine oil leak. It's where the turbo oil return line enters the top of the sump. I believe there is an O ring at that junction that needs replacement. The turbo and exhaust manifold will have to be removed.

While the engine was still warm I drained the old oil containing the SeaFoam that leaked past the piston rings into the sump. I was going to replace the oil filter but the one I purchased has the wrong thread. It must be for the 2.4 liter instead of the 2.3 liter turbo. I can't return it because I had already prefilled it with oil.

[Ozark Lee]

I was going to replace the oil filter but the one I purchased has the wrong thread. It must be for the 2.4 liter instead of the 2.3 liter turbo. I can't return it because I had already prefilled it with oil.

That is curious - I have 2 each of both flavors (2 N/A cars and and 2 turbos) they all take the same Mann W917 oil filter.

...Lee

[FlipIt]

I recorded the old filter number (Puralator L14670) and asked my local parts store to find an equivalent since they don't carry Puralator. The Fram equivalent is PH16 which has the same thread but is a shorter length. I looked up the filters for 95 thru 97 850 Volvos (turbo and n.a.) and they all showed Fram PH7328 which is the one I previously purchased. I suspect the threaded adapter has been replaced due to worn threads and an incorrect one was installed. I may order a new adapter to prevent future owners from encountering the same inconvenience I have experienced.

[FlipIt]

I was wrong about the oil filter adapter thread being different. I encountered the same problem with the second new filter and then noticed that there is a semi-rigid hose that is routed so close to the filter that it interferes with alignment when starting the threading. I deflected the hose and both filters screw on easily. Both Fram filters are shorter (less capacity) than the Puralator that was installed.

I was able to remove the allen head screws that hold the turbo oil drain but could not remove the pipe because of the adjacent water coolant pipe shown in the photo below.

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I realized that if I removed the three banjo bolts securing the two water connections and the other oil connection I might be able to move the turbo aft enough for the exhaust manifold to clear it. After removing the banjo bolts I was able to extract the oil drain pipe and confirm there was no seal on the pipe or the sump to prevent leakage. Even so I am surprised it leaks so fast since the tube is inserted at least 3/8 inch. I suspect there is pressure in the crankcase blowing the oil out thru the least restrictive opening. It was not difficult to remove the three turbo to downpipe securing nuts or the four turbo to exhaust manifold securing nuts. Then I tied the turbo with cord as shown below to support its weight but allow movement aft.

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I was able to remove 9 of the 10 exhaust manifold nuts/studs with a medium depth 1/4 inch drive socket I purchased specifically for the task. About half of the studs came out instead of the nuts. Access to the last nut was prevented by the EGR tube adapter so I loosened it with a flare wrench. My box wrenches are all 12 point which will slip on a hex nut or bolt that is very tight. I was able to work the exhaust manifold up and past the turbo without having to remove any of the vacuum connections or the air supply hose. In looking at the manifold (shown below) I realized why there were exhaust leaks.

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I assume the previous mechanic had the same number of studs come out that I did. A thick sealant had been non-uniformly applied to the gaskets to keep them in place on the manifold. The sealant had apparantly hardened prior to the installation of the manifold leaving numerous cracks for leaks. I noticed when the engine ran for about 20 minutes that there was smoke coming from the manifold. I just assumed that there was still oil on it that had not yet burned off. You can see on the extreme left in the photo below the EGR tube adapter almost completely blocking the hole for the 10th mounting stud.

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Today I ordered new gaskets, an EGR tube port plug and some seals. I attempted to remove the adapter using a 22mm 6 point socket connected to a 1/2 inch breaker bar. I used a 15 inch Crescent wrench to prevent the manifold from turning while hammering the breaker bar with my 4 pound hand sledge. I was not successful. I sprayed the adapter threads with PB Blaster and will continue spraying for a couple of days.

[boosted5cyl]

Enjoy!

http://overt.ie/files/racing/video/SpotTheOilLeak.mov

This is my from my T6 (again!), I was loosing 1qt every half mile. Didnt leak until it it 2000RPM ish, oring from the oil return pipe on turbo #2 was toast. $2 (and some more swearing) later, all fixed

[RyanGLT]

Boy, I tell ya....when you're done with this car and ready to sell it - somebody is going to be getting a well running car. This is a very interesting thread.

The information people are providing you here is the very reason I decided to become a contributing member. The guys on this forum know their stuff and are more than willing to help in any way they can. Can't beat that.

[FlipIt]

I finally received by parts order containing the correct coolant pipe to head bolts. I replaced my substitute bolts with the new ones and kludged together a cooling system pressure tester using a tire pump, some hoses and adapter fittings. The system leaked at the head/coolant pipe connection. With the exhaust manifold removed I was able to detect that half of the original gasket was still attached to the flange in addition to the new gasket. Fortunately I purchased and received another gasket in my parts order because the one I installed is now distorted by the old gasket remains. I will spend some time making sure the head and flange surfaces are clean, install another gasket and repeat the cooling system pressure test.

[FlipIt]

My coolant pressure test finally passed so I installed the exhaust system with new gaskets, connected the turbo lines, connected the air tubes, added coolant and engine oil, installed and connected the battery. I cycled the ignition key a few times and checked for fuel leaks. Then I cranked the starter and the engine immediately started even though it hadn't run for a couple weeks. No exhaust leaks at the exhaust manifold, turbo or down pipe! No coolant leaks where the coolant pipe attaches to head or at the turbo. No engine oil leaks at the turbo or where the drain line enters the pan! No ATF leaks! I am very pleased!

The engine idled very smooth and quietly. After it reached operating temperature I tried different engine speeds. It was very responsive and sounded strong with no load. I eventually raised the speed to 4,000 rpm and held it there checking for blue or black smoke from the tail pipe but didn't see any. I won't be able to check the turbo boost until I can drive the vehicle and load up the engine.

I purposely left the engine oil dipstick up so the crankcase was vented. As I suspected, once the engine warmed up puffs of smoke emitted from the dipstick. This means that the crankcase ventilation system is clogged. I know the path is open at the main intake fitting because I soaked the fitting with SeaFoam and blew thru it with a test hose. No doubt the crankcase ventilation system is clogged so today I removed the intake manifold. I noticed that one of the grommets/insulator (not the O ring) is missing between the injector and the manifold so I ordered 5 new ones. They won't arrive until this weekend. I also installed the new torque rod assembly.

[FlipIt]

I removed the oil trap and using various sizes of hoses was able to easily blow thru all ports in the trap and on the block. I soaked the oil trap overnight with the rest of my SeaFoam, drained it and installed the crankcase ventilation system. Since nothing was blocked I'm hoping my dipstick tube puffs of smoke were due to the pinched hose shown in the photo below.

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I installed the intake manifold, new injector seals on the fuel rail, the electric cooling fan and shroud, a new throttle body gasket and then connected all of the intake hoses and tubes. I even managed to install the two piece exhaust manifold heat shield that keeps the paint from blistering on the hood. Being almost out of gas I decided to make my first drive to the gas station about 2.5 miles from home.

When backing out of the garage the brakes squealed due to all of the rust on the rotors. By the time I had driven the two blocks in my subdivision the ABS warning light extinguished. I suspect it came on when I ran the vehicle in drive to check the transmission while all wheels were off and the vehicle was sitting on jack stands. Having the front wheels going 25 mph and the rears not moving must have been confusing to the ABS.

Almost as soon as I pulled out of my subdivision and started down the hill toward Wal-Mart's gas station a big arrow on the dash started flashing and the Check Enging light came on. I suspected it was related to the transmission but couldn't confirm that because I had left my owner's manual at home. At the bottom of the hill another symbol illuminated that I thought might be related to my cooling fan. Since the engine temperature was still normal I pressed on. Next the fuel low warning came on but I made it to the gas station without running out of fuel.

I read the DTCs in the parking lot but didn't have my manual to decode the only one shown: P0500

I decided to attempt to return home. Things went OK until I started up the hill to my subdivision entrance. It seemed like the transmission needed to shift down but wouldn't and the engine couldn't pull the hill in overdrive. I shifted to low but could only depress the pedal slightly or the engine would start to stall. Fortunately no one was behind me and I creeped up the hill at 5 mph and then thru the subdivision to my house going 10 mph on level ground. I learned that the flashing arrow indicates automatic transmission fault and P0500 is vehicle speed sensor malfunction. Hopefully, the engine just went into limp mode when the VSS faulted. The other indication was low coolant level because the thermostat opened up dropping the level in the pressurized overflow tank. The wagon is now back in the garage for diagnostics. The first thing to check is the ATF level with the engine warm. I've read that the VSS fault can be triggered by the ATF being only 1/2 quart low. I checked it with the vehicle on jack stands but the vehicle may not have been level.