'99 T6 Blown head gasket\cooling system questions

Post by **boosted5cyl** » 12 Oct 2010, 13:27

So yesterday while checking something else, i started getting steam from the exhaust, in amount much greater than normal so Im pretty damn sure its the head gasket...

lately the coolant temp gauge has been randomly falling to 0 as if the connection is bad and there was a corresponding code for this stored in the ECU.

So two days ago, lieu of winter I drained the coolant and topped off with distilled water along with some pestone rad flush. All seemed to go well, I turned on the heater (plenty warm!) the cooling fans cycled. Coolant level was good. Took it for a test drive, coolant level still all good. Drove it to work the next day, coolant level still good. Got home and once again, the coolant temp gauge fell to 0, so I hooked up the laptop, and it was giving me a reading from the temp sensor (80 something degreesC). I disconnected the sensor and the reading on the OBD readout fell to -40 or thereabouts. Is their another sensor that the gauge gets it reading from or does it quit working if there is a code for the sensor?

Any tips for replacing the headgasket?
How can I test the cooling system for blockages?

Thanks in advance.

Post by **boosted5cyl** » 16 Oct 2010, 13:45

Thing are getting interesting.....

I got a cooling system pressure test kit thing and got it up to 13PSI before the cap started leaking. Replace the cap with a new 150Kpa (21PSI) one. It released pressure at the same 13-14PSI range, so I guess the gauge is crummy. No visible leaks into the cylinders, however there was a very obvious leak at the back of the motor. The water was dripping off the heatshield that sits on top of the transmission, underneath the exhaust & tubos onto the floor. Couldnt for the life of me find the exact source of the leak though. At this stage I only had distilled water in the system, so I emptied it and refilled the system with coolant, now the leak is gone!

Post by **boosted5cyl** » 16 Oct 2010, 17:52

....tumbleweed

Found the leak, it was coming from the hose going into the heater core. Water was dripping down the pipe. It didnt start leaking until the coolant was drained and replaced with pure water again. Looks like ill have to dig deeper. Cooling system holds pressure within 1lb for 10mins+

Post by **JDS60R** » 16 Oct 2010, 21:38

Pressurize it and let it sit for 10 min- then come back and pressurize again. (this removes pressure change from any expansion of hoses).

Then take to 22psi and let sit for an hour. You should not lose any pressure.

Post by **boosted5cyl** » 21 Oct 2010, 14:17

I haven't tried the exact technique for the cooling pressure test that you described above (22PSI, let settle, 22PSI again and check after 1hr) but ill give that a go tonight. I pumped it up to 20PSI yesterday and left it overnight, ill see where its at today, I did note a teeny-weeny ooze of fluid at the top radiator hose connection.

I got a leakdown tester and a compressor, put 90-100 PSI into each of the cylinders at TDC and have not found a leak into the cooling system. Beginning to wonder if I imagined the steam from the exhaust LOL.

Post by **boosted5cyl** » 21 Oct 2010, 19:24

OK, pressurized cooling system to 22PSI, let sit for 10mins, set to 22PSI again (dropped about .5psi) and after one hour the pressure dropped to 21.5PSI. No visible or audible leaks.

Post by **boosted5cyl** » 03 Nov 2010, 10:35

Alright so I've gotten the head off and its off being pressure tested today. Broke one of the bolts on the way out, but luckily it just about stayed in tact to come out in full. A lot more carbon on the head and pistons than I expected, especially on cyl #4. No signs of a leak that I can find, there is a small nick about 3mm long on the head and gasket by one of the cylinders, doesnt appear to be leaking there however. Doesnt appear to be any distortion on the head so fingers crossed. Now for some pics I have some of the head too but wont be able to post them until tonight.

Post by **boosted5cyl** » 08 Nov 2010, 15:14

OK update.....

Head is back from the shop, cleaned and skimmed (was .007 out apparently).
Got the inlet manifold and ETM all cleaned up nice as well as the cylinder block and aluminum turbo piping.
Most of the carbon cleared off the piston crowns (was nearly 1.5mm think in some spots!).
Valve cover cleaned up, but I think I might get it steam cleaned to get all the crud off.

Think I might hold off on rebuilding the turbos, i pulled apart #2 and it has writing on it like it has already been rebuilt. My theory is that the compressor wheel hit the housing before my ownership and was rebuild. The wheel looks fine. Heres some pics. This is how turbo #2 looked before cleaning....Looks pretty damn good to me.

Any ideas on how much radial and axial play is permissible on these TD03-8G turbos?
According to their staff, this kit is suppsedly compaible with the turbos in the T6 (SKMTD03TF035): http://baeturbosystems.com/turboservice ... ent-2.aspx

Post by **boosted5cyl** » 14 Apr 2011, 20:13

Well im posting back on this to let everyone know this was an epic fail. I never found a head gasket leak, reason being that it didnt exist!!

The symptoms I experienced returned and got worse. Smoking and steaming badly at idle, but at idle only. I isolated it to the PCV system which I serviced. If I pulled the dipstick or the top PCV pipe off/out, the symptoms would eventually stop. I figured there was excess crankcase pressure from somewhere. I ran a leakdown test, cyl #2 is leaking into the crankcase really bad. I got readings of 13% loss on all cylinders except #2 which was 35% and was audibly MUCH worse than others. In fact if I put my hand over the oil cap for a couple of seconds you could feel the pressure building. Other cylinder is would probably take 30seconds or more. For now I'm leaving the dipstick a little bit loose to reduce the pressure in the crankcase.

Good news is that the valves I relapped are sealing perfect

Here's the compression readings from a year ago(https://www.matthewsvolvosite.com/forums ... 11&t=28784):

1 - 130psi
2 - 180psi
3 - 190psi
4 - 90psi (sometimes got reading as low as 30!?!)
5 - 190psi
6 - 190psi

Go figure! a year ago, 2 was fine, 1 was borderline and 4 was shot. Now, a year later 4 is fine, 1 is fine (on leakdown anyway) but 2 is effed. Only work that has been done motor wise was the top end rebuild. I'm running a course of AutoRx so with some luck I may only have a coked up ring pack on 2. I'm doubtful though.

mlanctot · Post by **mlanctot** » 28 May 2011, 11:28

Putting the head back on the car. AllData states to torque head bolts to 45NM. For final pass torque 103 degrees. Any body know what that means?

thanks