Cooling system gradually losing cool?

Post by **jmailloux** » 25 Jul 2011, 22:46

Hi all,

My 1998 V70R, with 156k on it, seems to be running hot, gradually more and more so. The temp gage stay locked on the 3 o'clock position, but the cooling fan seems to be coming on in cooler and cooler outdoor temps, running longer, and I hear it running after the engine is turned off more and more (it does turn off by itself). Sometimes the car smells a bit like it is burning off some debris or fluid leak.

Last time I changed coolant was 02/2008, at 130K, which when I got a new radiator and hoses. I put in a new thermostat (87 deg), new coolant temp sensor, and new cooling fan relay in 03/2011 at 153k. I guess that is when I noticed this starting to happen. Coolant stays up at the "max" level, no appreciable loss of fluid. Original cap on the tank, if that matters.

I normally have no drips on the floor, but just as I write this, I find I have what looks and smells like engine oil, probably silver dollar sized spot, center, under the front anti-sway bar. It is probably flowing back over the catalytic converter, giving me the burning smell. Related to my cooling problem? Probably not I would guess.

Anyway, back to my cooling problem: I realize that I probably should have changed the coolant before now. It's on my list to do now. I will want to clean and flush at the same time. Is one of the Prestone flush kits worth it?

Is this just weak coolant, or should be looking for something bad first, like a leak between the trans cooler and the radiator? How do I look for that? Or could this be a radiator that is getting clogged up and less effective?

Thanks,
Jim.

Post by **Juan62** » 26 Jul 2011, 03:46

Coolant problem; when you changed the thermostat/temp sensor/hoses, that was the time to put new coolant in, climate control set to heat on high while engine is warming up. If no coolant leaks (includes under front pass carpet), flush and replace with Volvo coolant...2 gallons. If you mix you coolant with water, make sure its distilled water Not tap water.

Post by **jblackburn** » 26 Jul 2011, 07:57

I have always just flushed with distilled water. Run the car up to operating temp and let the thermostat open, let it idle for 3 min or so like that, and then dump the water and repeat once more before filling with coolant.

I normally have no drips on the floor, but just as I write this, I find I have what looks and smells like engine oil, probably silver dollar sized spot, center, under the front anti-sway bar. It is probably flowing back over the catalytic converter, giving me the burning smell. Related to my cooling problem? Probably not I would guess.

Look at your turbo. Might be a cam seal or oil dripping down from the oil return line - it's got to be leaking heavily for it to reach the ground.

Post by **jmailloux** » 26 Jul 2011, 12:16

Thanks for the info! Yep, I will run the car, check for coolant leaks, flush and put new coolant in. Going to use the Volvo coolant. I do drive in some pretty hot weather: Should I put in 50/50 mix? Or is the pure coolant better for cooling?

Next question: The heater hoses are original; this might be a good time to replace them. OEM from dealer the best or is there a cheaper but still good alternative? And any tricks to replacing them, especially with the turbo right there where the hoses go into the firewall?

As for the turbo, I thought it might be the source of the leak. I'll get the car on the ramps and take a look. Such fun.
Jim.

Post by **jblackburn** » 26 Jul 2011, 12:22

50/50 will be fine; you might do a 60/40 mix if you drive in weather regularly above 100F. Never use 100% antifreeze.

Radiator and turbo coolant hoses ABSOLUTELY should be replaced at this age before they blow up and overheat the car and leave you with a warped cylinder head.

Post by **jmailloux** » 26 Jul 2011, 12:37

Thanks. I was just pricing heater hoses and the firewall coupling on IPD. Going to run $160+ for the set for OEM. One expense I can do without They look OK; I will give them squeeze tonight, see how they feel.

Unfortunately, I had a garage do the work when the radiator and hoses were replaced in 2008. I am unsure if they replaced "turbo coolant hoses" (didn't know I had such things in this car....guess I should have known). I know the garage did the upper and lower radiator hoses then, since the old radiator's upper hose fitting cracked off when they tried to pull the hose (hence the new radiator). Where are the turbo coolant hoses and is that something the garage would have replaced if I said "replace the cooling system hoses"? Or would they not have thought of that?

I will dig through my car maintenance records (receipt) tonight and see if I can figure out if they replaced the turbo cooling hoses or not.

OEM recommended for the turbo hoses? Or SAMCO or something?

Thanks Jblackburn!
Jim.

Post by **jblackburn** » 26 Jul 2011, 12:42

I've never seen them replaced before, since they're about to blow up on nearly every turbo model I've been under.

https://www.matthewsvolvosite.com/forums ... =1&t=40514
^See that for pictures/part numbers. OEM HOSES ONLY!!!

Post by **jmailloux** » 26 Jul 2011, 12:57

Thanks! Off to the dealer I go. I am fairly sure the turbo cooling lines have not been replaced. I will be spending some time with my hands up around the turbo, again.

Since I am down by the turbo anyway, I will try to work on that oil leak as well. I will read up on the forums before I ask about that one......

Jim.

Post by **jblackburn** » 26 Jul 2011, 13:04

See that fat metal line? That's the oil return line and is one of the prime suspects for leaking. If that line appears dry like the picture below, but the rest of the turbo is covered in oil from what looks to be above, look to your rear cam seal on the rear-most cam (behind the cam sensor to the rear of the engine from the distributor).

If that cam seal is blown out, your PCV system may be in jeopardy as well if you have not already replaced that.

Post by **jmailloux** » 26 Jul 2011, 13:19

Sorry to bug you, but now you have got me going: The oil return line is in the right 1/3 of the first picture, right, with the two bolts bolting it onto the turbo? What do I buy? A new oil return line, or just the gasket, or both? I am betting (and hoping) it is the oil return line. I really don't want to have to clean the whole PCV system right now so I hope it's not the cam seal...And no, I have not replaced either the cam seal or the oil return line seal before.
Thanks,
jim.