Ok, our 95 850 Turbo has been losing coolant for about a month now. Usually it will lose about a pint (or the equivalent of the overflow reservoir) every 200-250 miles or so. I have not been able to really look at it due to a lot of work commitments, until today. Anyway, I drove it about 30 miles today, and when I got it home my son said he noticed a couple drips coming from underneath it. I crawled under and the drips were definitely coolant. Looking further, the passenger side frame rail under the engine was wet with coolant, and the top of the frame rail area under the firewall behind the engine was wet also. Lastly the passenger side inner CV joint boot was wet.

I pulled the timing belt cover off and the belt area was dry as was the water pump pulley itself, but it looked as is the timing belt tensioner cylinder had some fresh corrosion on it and some areas of the plastic timing belt cover looked like they had been damp. I could not see the bottom of the water pump itself to see if it was wet/leaking. The water pump was changed about 90,000 miles ago during a timing belt change, and the timing belt and components were changed again about 20,000 miles ago but not the water pump. Also, this car blew a radiator hose on my son about a year ago and got hot enough to blow the head gasket and warp the head before he noticed it (go figure). All cooling system parts (except the water pump) were changed when the head and gasket were replaced. The car has been running great except for the coolant leak

What do you think? I'm thinking the water pump is leaking. I have a 450 mile round trip I have to go on before I would get a chance to change the pump, so I plan on religiously keeping an eye on it as well as the temp gauge and coolant level idiot light.

Anyone have any other theories outside of the water pump.....please let me know.

Glenn

 

Wow, 54 looks and not one reply.......either no one has any ideas that can help, or this forum has stopped being as good a resource as it used to be............

 

LOL, pull the wheel and the timing belt cover to look at/near the bottom of the water pump. If it is leaking in the summer and while driving, I wouldn't even start it if you don't have to.

If the pump comes apart, it will toss the belt and destroy the car. I'm sure you guys are not going to change the head again, you were on the edge last time you had to do it.

What kind of pump was installed when it was changed 90,000 miles ago? Has the turbo return line been replaced?

Coolant roulette is not a good game. Most lose.

 

Hi RSPI,

Glad to hear from you. Yeah, the turbo coolant return line was replaced when I did the head job. It has been running great except for the now coolant leak. The leak definitely appears to be coming from the lower passenger side of the motor, so I am definitely thinking water pump. The pump on there right now is a Hepu brand. I changed everything in the cooling system except the water pump when the car was overheated. I'm starting to think the extreme heat when it overheated compromised the pump to block gasket. I guess one way to check it is to pull the wheel and timing cover, and let it idle while I keep an eye out for leaks.

Glenn

 

I doubt that but you can check the torque on the bolts. If the pump is leaking a few drops after sitting overnight that is no big deal but it should NOT leak at all while warm, especially when running warm.

If you watched the video, mine was loose and the belt was hanging off after driving about 180 miles. I was hesitant to drive it at all but I was on the highway and took my chances to get 3 miles down the road. The next real town was 34 miles away and I didn't chance it.

 

Well it is leaking a bit when it sits, but that could be residual from when it leaks while warm. It definitely appears to be leaking when it is driven around. Either way, I picked up a new water pump and gasket on the way home from work last night. If I get a break from my honey-do list and work, I will get a chance to change it soon. I pulled the battery so my son cannot drive it as I just don't want to risk it. He can drive my car or his brother's.

One question, do you use gasket sealer on the gasket when you replace it or not? I would use it at the very least to hold the gasket in place while I put the pump in.

Glenn

 

Yes I do use a little gasket sealer to glue the gasket to the pump. Never on the other side and hopefully not enough to ooze out when I bolt it on the motor.

Good call on not driving it. If it's leaking while driving it is past time to replace it.

 

Well, it turned out to be the water pump. It was leaking from the bearing. New pump is in and it seems to be leak free. The only thing that gave me trouble was getting the timing belt back on. Every time I checked it the darn intake or exhaust cams always ended up one tooth off. After 5 tries I got it right. I have changed several timing belts on 850's and V70's and have never had a problem.

Well, at least it is back together, running strong, and seems to be leak free!

Glenn

 

I didn't even pull the belt when I replaced my pump last week. I pulled the tensioner, pulled the belt off the water pump and tensioner roller, then hung the slack of the belt up near the idler roller and pulled the pump. Took about 2 hours.

 

I just had my timing belt with both pulleys replaced after 70000 kms and since it costs just 60usd for a new pump (not oem) so i had it replaced. I had a look at the old pump (also not oem) it had some blue coolant residues at the bearing and when i turned the pump with my hand,it was making a little grinding noise. I was right to have it changed before it breaks. I think it's a good idea to have it changed the same time as timing belt. In your case,i think it's way overdue.

 

I have seen after market water pumps go bad in less than 40,000 miles. If you have a choice, only use Volvo (Aisin) or Hepu water pumps.