This topic is now archived and is closed to further replies.


S90 hard to find coolant leak found

Recommended Posts

Had a coolant leak that only occurred as the engine coola off after driving. First thought it was the water pump, replaced it with new gasket and it still leaked. 

Next fear was head gasket leak because it came from above the water pump, but there's no water mixed in engine oil.  The coolant was coming from the head gasket area when looking from below the car.

Finally after removing some parts, timing belt, timing cover, ran a pressure test on the block when engine was cold revealed it was the heater hose gasket coming out of Cylinder #1.  This $5 gasket was impossible to locate until you take many components off.

See the photo from a similar engine. The vertical hose on the far end was the culprit. Thick hose in the middle goes to the water pump.  You can see how this leak could lead you to believe it's a head gasket leak.


Share this post

Link to post
Share on other sites

  • Similar Content

    • By fzr1483
      New to the forum and first time owner of a Volvo.  Just picked up a 1995 850 Turbo wagon for $800.  That price of course came with a lot of mechanical issues.  I got so much valuable information about these cars pre-purchase from this forum so I thought I'd post my question.  The car has unknown mileage because the speedo gear broke.  Odometer is stuck at 123k mi.
      The PCV system is blocked.  Using the latex glove on the oil cap trick, there is definitely positive pressure instead of vacuum.  There is no smoke from the dip stick though.  Looking inside the oil filler cap and at oil on the dipstick, it looks pretty clean.  I'm planning on replacing the PCV system and will get a better idea of whether or not to pull the oil pan.
      The car drips oil on the right side of the engine.  After washing that side of the engine with the timing belt cover off, the cams and tensioners were covered in oil after a 15 minute test drive.  The majority of the oil seems to be toward the rear of the engine, over the CV boot.  Based on what I've researched, I'm thinking it's the front cam seals.  What other seals should I take a closer look at on that side?  With the unknown mileage and the owner stating they don't know when the timing belt was changed, I plan on replacing the belts, pulleys and water pump.  That said, let me know what other components I should inspect while I have all that disassembled.
      Now the spark plugs had serious oil sludge on top of them.  There was also some oil under the spark plug cover on the head.  Are there any problem areas I should inspect for the source of the oil?
      Also here are the results from my compression test.  I think I saw somewhere that factory spec on the turbo is 160-180 psi?  The wet test leads me to believe that the piston rings are worn.  What's has me a bit confused though is that exhaust doesn't smoke.  Plugged PCV and potentially bad rings.  Shouldn't I see some symptoms?  My other question is how bad are the dry test compression readings?  Is this maintenance I can defer or do I need to take care of it asap?
      Cyl    Dry   Wet
      1       130   180
      2       145   170
      3       145   165
      4       140   170
      5       120   145
      Also, does anyone see potential head gasket leak with these results?  The reason I ask is because the coolant overflow bottle has a dark brown stains inside.  But the coolant itself is clear (or greenish rather).  I tried to gauge if the coolant level rises after driving, but it's over filled as is (1/4 in above max line), so I will drain some coolant and try again.
    • By digital.aaron
      So I just got a new-to-me Saffron R this week. I bought it from a fellow Volvo enthusiast who had rescued it from Seattle and brought it back down to Portland a couple months ago. He did a lot of maintenance work on the car, and made good progress to getting it back into shape. He told me that he drove it occasionally to work, and sometimes on the weekend, as he was replacing worn out parts and giving the car a general tune up. However, he noted that usually when the car got up to temp, he could hear a faint hissing coming from the reservoir, and every two or three days he'd have to add coolant to the res. He thought he might have a slow leak in the res, so he swapped in a brand new URO res (although i thought for sure he was talking about a euro reservoir...), but he said it didn't seem to seal at all, so he returned it, and put the stock one back on. He then suspected a bad head gasket was causing the res to get pressurized. So he did a compression test, and all 5 cylinders came back the same. He also did a leak down test, but I don't remember the numbers he gave me. They all sounded normal. Before I left his place with the car, he told me that even with the hissing, and needing to fill the res every few days, that the car still ran dead center on the dash coolant temp gauge, ever when letting it idle for over and hour. 
      So of course on my drive home, about half way to my place, I see the temp needle start to climb. i stopped and popped the hood, and could definitely see steam coming from the res cap. I figured that the problem was probably the cap, since that was one item he didn't replace. I ended up picking up a new URO cap and a new res. I first tried just replacing the stock one with the new URO one, but I had the same thing happen. I was driving fine for about 15 minutes, then BAM, the temps started climbing past normal. I popped the hood again to see some water boiling in the res I babied it back home, making frequent stops to let the car cool.
      Next, I decided I would try to put a new res in. I got a URO one, and tonight I swapped them out. I put the URO parts in, and took it for a drive. Again, for the first 15 minutes or so, the temp was pegged dead center. I then stopped to see if I could find any steam or leaking water. I saw the engine compartment around the reservoir was wet, but no steam, and no water gushing out of the cap. I decide to continue on my testing run drive a couple more minutes before turning around to head back home. As I'm making my way down the road, I see the temp start to climb again. I pulled over and popped the hood so see water coming out of the cap, and a tiny bit of steam. So I let everything cool down, and then took it slowly back to my house.
      So my questions are: 
      * Has anyone had a similar issue before?
      * Might a Volvo-branded cap and res help solve my problem?
      * Does anyone think this might still be a HG issue?
      I appreciate any help and/or input anyone can provide.
    • By Caffiend
      Hello! I'm new to the forum. I've had a 1997 850 AWD with 5-speed manual for about 9 months now. Cosmetically a little worse for wear but the pre-purchase inspection told me that it was mechanically sound and had some recent work done. Before Christmas I noticed that my oil was starting to look like milky coffee and a web search along with a convo with my mechanic suggest that it is coolant leaking in to the oil through a blown head gasket. Losing a bit of coolant over time seems to confirm that. I drove it for a bit like that since the coolant temp gauge showed normal but ended up putting the car in storage since I didn't want to damage the motor and couldn't afford to fix it right away. I've thought about just selling it but I'll have the money to fix it soon and I do like the car; it's comfortable, space for days, looks kind of funky and I know Volvo wagons with stick are rare as hen's teeth. Ultimately if I did keep it and fix it I would like to swap out the low-pressure turbo and squeeze some more juice out of the car.

      I'd likely get at least a slight 'friend discount' from my mechanic but at this point I don't know if it's just the gasket or if the head or block are cracked. I've thought about running come sealer through the coolant and seeing how that goes but that doesn't bode well for long-term integrity of the motor. I could try to track down another motor or even swap in an HPT motor but I'm worried that would be even more expensive and possibly run in to transmission mating issues.

      What would you suggest? Should I get it fixed, swap the motor, or sell it and run screaming?

      Thanks for the advice!

      - Justin
    • By denniswright1
      2001 v70 t5 Blew a heater hose line , replaced it and now I think head gasket or something else bad wrong blows everything right out the muffler. Why would this both happen at same time or does anyone have any other scenario it may be? Is head gasket difficult to replace? Or expensive?
      Thank for any help
      My 95 850 Turbo wagon has reached a critical point in its life. At 215,000 miles I have the dreaded disappearing coolant loss syndrome. Oil analysis confirms that the coolant is going places that it shouldn't. Both a pressure test on the cooling system and a compression test came back with pretty good results for a car with this sort of mileage. The wagon is currently in the competent hands of Bill Behrens in Easton, MD, Awaiting a head gasket waterpump , and timing belt. My question is, should I just bite the bullet, and look for an other engine. What are the chances that I have a cracked head or worse. Has anyone had their engine replace by a shop? What is the average cost and what is the downside?

      The car is in pretty good shape. It has Koni shocks IPD sway bars, and just about everything else in the front suspension has been replaced. A lot of things have been replaced or added in the past year, Windshield Oil Trap, Plugs and wires. I replaced the the turbo with an 18T a few years back. I have had this car since 99, and love it.

      Any and all opinions appreciated