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This is a car I have been going thu the last few months for my daughter. I noticed the last couple weeks that the coolant fluid level was down. I checked the oil dipstick and saw some brown froth residue on the end so I immediately thought blown head gasket, but not convinced. Added some more coolant to reservoir and it seems to be at same level. Engine runs fine. My daughter only drives short distances 5 or 6 miles one way to school so I am wondering if this is a condensation issue since I noticed this when it got cooler outside. Also noticed some brown residue inside the dip stick tube which could account for some as I pull the stick out. Haven't pressure tested the coolant system yet or performed compression test. I opened the reservoir tank a couple hours or so after the car was driven and it still had pressure in the system which is good news. The coolant itself is clean and clear, no oily residue. The ATF fluid is w/o the brown froth residue so I don't think the coolant is going there. Any thoughts? Want to continue improving the car but don't want to sink any more money if it is a head gasket. The car has over 200K miles. One other thing, the crank case breathing system has not been cleaned and is definitely clogged.
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This happened to our 1997 960/V90 (basically the same engine but 6 cylinder) when my wife was driving very short trips to work. If you're not already doing it, switch to synthetic oil. Also, you can clean the pcv system by pulling the oil drain plug and dumping a quart of cheap engine flush down the breather tube where the flame trap connects. In a unrestricted system, it will basically drain right out. Longer trips will definitely help. Ours caused excess crankcase pressure which blew the rear exhaust cam seal and caused major oil leak.
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Have you poured this down your hose when the system was clogged in an effort to open up the PCV system? I know mine is clogged and would like to find a easier way to clean than having to pull off the intake manifold and all that entails.
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Pouring cleaner down the large tube will help a little, but, it will do nothing for the small vacuum hose which clogs faster.
Removing the intake manifold allows you to actually replace the hoses and inspect the two holes in the block where the oil passes through. It also gives you a chance to clean out the throttle body, and the EGR if your car is so equipt.
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Keeping it running is better than buying new
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Hi Klaus,
I would like to focus on the simpler potential causes first since my time is very limited. What would be the simple fast things to check first that may correct crankcase pressure issues? PTC valve & hoses, ...others? This is a turbo engine.
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For turbo engines, cleaning out the PTC valve can never hurt. But this is not an 'easy' task and may not rectify the problem. Give yourself 2-3 hours for the first time.
Remove the air supply line from the air filter to the turbo. Two clamps, 3 vacuum hoses, and the electrical connector at the PTC. Very carefully remove the PTC nipple from the intake. You should see completely through the hole in the PTC, which is not really a 'valve' but a copper heated core. Using a small screwdriver or other scraping tool, remove the coke lining the core. The opening should be the same size from one end to the other. It does not need to be shiney clean.
I spray the rubber connector at the base of the PTC with silicone before very carefully inserting it back on the air hose. If it doesn't sit flush and the rubber is compressed on the intake side, take it off and try again.
Before reassembling, try attaching a hose to the small vacuum line and blowing through it. The small hose goes to the intake manifold by cyl #1.
The large diameter hose at the PTC is routed to the separator box. Try not to bend it as it is rigid and can crack. Plastic/heat/age...
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Keeping it running is better than buying new
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Thanks Klaus - expecting some unusually warm temps this Sunday near 70 so sounds like a good time to go thru it then.
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I toyed with the gunk on the dipstick for a while on a couple of 850s.
Even with an oil change, the gunk can remain in the tube.
I eventually used a couple of large chenille stems to clear the tube - chenille is a craft supply that looks like a large, colored pipe cleaner.
Cleaning the tube and taking a 20 mile drive yielded a clean dipstick - a few short trips in the cold made the gunk come right back.
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Good news, changed the oil last night and no brown foam in the oil, just dirty. I do remember now why my coolant was low - about 2 1/2 months ago I changed out the thermostat which was broken causing the engine to not reach operating temperature once the weather got cool which added to the condensation I'm sure. I lost a little coolant in the process and never topped it off. When I went back to check oil and other things recently I noticed it was low and assumed the worst. Now I can proceed with the rest of the rework :)
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I'm with the others on the condensation. Though it wouldn't surprise me that you need that PCV service. If it's never been done, that's at least 20 years...
Re. the condensation, like Klaus, I used to have a condensation issue when my daughter used the car in high school - all short trips. Once she started commuting to college (44 miles away), the condensation issue went away.
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Our 2.5T did the same thing when it was in need a PCV servicing. Once I cleaned out the PCV system the condensation cleared up.
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)
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My money is on condensation! Common winter problem. Head gaskets rarely go on 850's. This has happened to both my 240 and 850 in some, but not all, winters. 100% agree with Klaus' suggestion to get the engine good and hot as this worked on my 850 in the past. Drive the car regularly on the highway with engine speeds of at least 2500 rpm for 15 minutes plus. That should cure it.
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I agree with the conclusion that it is a cold running engine. If it is not a turbo, clean the PCV flame trap as soon as possible. If it is a turbo, remove the PTC nipple and clean it out (on the intake air hose from the filter to the turbo).
Drive the car for at least 30 minutes, once a week, to get the oil hot and burn off the impurities/water. My daughter had a 2 mile run to high school, I told her to shift to low (2nd) when above 25mpg - made driving 'fun'.
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Keeping it running is better than buying new
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Sorry, meant to type "Klaus"
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Hi Claus,
Sorry, should have said this is a turbo. Where is this PTC nipple? Is this just the plastic hose barb that is attached to the intake hose right after the air filter?
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The PTC nipple is a heated device so it has an electrical connection. If you break the PTC, a new one only comes as part of the intake hose. Check the bottom of this post and note the not numbered part below #9.
When I pulled mine out after 175K miles, there was just a pin hole through the PTC rather than 4-5mm space. Lots of scraping with a small screwdriver to get to the copper layer which is the heater element.
To get the air hose out of the car, it needs to be removed from the Turbo and all of the vacuum lines (3) get pulled off. The hose is identical from 1994 turbo through 2000 turbo engines if you need a replacement.
To check the air draw through the PTC, warm the engine, remove the oil filler cap, cover the cap with a latex glove, start the engine. If the glove inflates, you have a plugged up system.
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Keeping it running is better than buying new
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Klaus,
Thanks for your help again. Plan on changing the oil tonight to inspect it further and its due anyway. If I find the PTC valve clogged and unclog it the glove still might inflate due to blockages elsewhere in the PCV system right? Is the PTC valve just the first easy to get to (relatively) place to check? Also, you mentioned check at the bottom of your post for item #9, was there supposed to be a schematic shown?
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Ooops!
http://volvoforums.com/forum/volvo-850-16/ptc-nipple-anatomy-61885/
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Keeping it running is better than buying new
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Drain a little oil out of the crankcase after the engine has been run for a while. Does it look like a chocolate milkshake or regular used oil ?
Most likely the brown froth is condensation but it is worth checking out.
Greg
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