Clunky high speed down shift, Oil leak, AC trouble

[Mootman]

Hi, I recently bought a 1998 V70XC with only 89,000 miles on it. The car has three significant issues. Just curious if anyone else has experienced this. While driving at freeway speeds there is a noticable clunk or bump when I press on the accelerator and the automatic trans downshifts. The tranny fluid level is up where it should be. This is my first AWD volvo so I don't know if this is normal but it feels abnormal to my mechanical instincts. It is more of a feel than a sound, like driving over a small bump in the road. The car also has a substantial oil leak. The former owner took it to the dealer who said the oil line seal to the turbo was leaking. Is this a difficult repair for the do it yourselfer? It looks very tight space up there. Can it be done from above after removing the exhaust heat shield? The third issue is the A/C does not blow cold. When turned on, the compressor engages for 2 or 3 seconds and then disengages for 2 or 3 seconds. This happens continually at idle. After a while I noticed condensation forming on one of the A/C lines that leads through the firewall but no cold air in the cabin. The previous owner said they had the A/C recharged just 6 months ago. Any help with these three items would be greatly appreciated. Thank you!

[abscate]

You should drain some transmission fluid and have a look at it to get a feel for how the car has been maintained.

The oil return gasket is a struggle but doable. Certainly not worth paying people $115 an hour for labor and a $5 gasket.

The AC fix is called the 'bread clip' fix even though now most use zip ties rather than bread clips - it is searchable here.

[scot850]

As for the clunk, there are a few possible causes, and even though the car has a low mileage it is nearly 20 years old so rubber parts perish.

Parts to check:

Engine Mounts: Check the top and lower torque mounts for cracked/failed bushes. Lower torque rod is obsolete. The smaller rear bush
is the one that usually fails. You may have to buy the FWD polybushes for this and replace the rear bush.
Check the engine mount under the crank pulley (RHS end of engine). These can separate the rubber from the metal
mounting plate. You can check easily by removing the RH front wheel and supporting the car. Jack the engine at the
RH end under the oil pan slowly, and look through the RH plastic fender liner to see it the mount allows the engine to
lift and a gap appear between the metal pad mounted to the sub-frame and the rest mounted to the engine.

Prop-shaft : Jack the car up and support it! Crawl under and grab the propshaft at the front end and try to move the joint up and
down. If you can the front CV joint has started to fail. Proximity to catalytic converter accelerates failure.
Check the middle support bearing. Again rubber and looks like a donut. Look for cracks and splits as it will allow the
propshaft to whip and clunk under the car.
Check the support bush at the front of the viscous coupling case just to the RHS front of the case (just behind the end of
the prop-shaft rear connection.

There are possibly other issues, but these are the most common. If the propshaft has issues, you can remove it and run the car in FWD or have the prop-shaft repaired and re-install it. Colorado Driveshaft is the go to for many for the propshaft repairs.

Neil.

[Mootman]

Thank you both for the responses! I plan to do some crawling around to see what I can find. One other observation is that there is a odor coming from the fan ducting that smells a bit like burnt clutch lining. Is this what AC refrigerant smells like if there is a leak in the system?

[June]

No R134a has no smell. Burning smell must be either coming from the engine bay or maybe the blower motor. June

[Mootman]

Just to update my situation: I did the turbo oil return leak repair which was absolutely hellish but successful. An epic amount of work just to replace a gasket and an o-ring! No more dripping oil leak. There still is a small amount of oil running down, possibly dripping off the bottom of the turbo itself. Don't know what to do about that. As for the clunk(thank you, Neil), the upper torque mount bushing is shot and the lower left engine mount looks iffy. Has anyone installed the poly upper bushing and do you like it? Have not inspected the drive line yet, but found out that it had been replaced already with a used unit! Makes me wonder as to it's condition. I think I need a car lift! Still not sure about the brake/clutch lining smell coming through the fan ducting. The fan motor works fine, and the smell is most noticeable at start up and then dissipates rather quickly. Checked the pollen filter and surrounding area for any sign of rodents but found none. Thanks for your ideas!

[wizechatmgr]

I have the upper poly bushing on a 99 V70 XC. I'm told it transfers just a little bit more noise and vibration to the body. Compared to the failed one, I'll take the little bit of noise and lack of a clunk any day.

[wizechatmgr]

Nevermind, this was already addressed in a previous post. =)

[charleskennedy23]

Poly bushings... NO! NO! And *$&@ NO! They cause significant vibration and my upper bushing lasted less than three years before disintegrating! I ended up taking both of the poly parts out and replacing with OEM and am much happier now.

As far as installation goes, the transmission torque mount is a piece of cake to replace. I have heard that some people have a hard time with the upper engine bushing, but I put mine in the freezer for a couple of days and when I went to install it it slid right in. I didn’t even need to press it in even though I made the wood press per Robert DIY‘s video (

There are a total of 5 engine mounts... These two plus the engine mount on the passenger side are a snap. The front and rear mount are a bit harder, but there are lots of DIY instructions online to help you through it. I did all 5 on my 98 v70 and it made a huge difference!

[scot850]

The transmission torque mount/rod is hard as they are no longer available for AWD P80's new. I tend to find on the AWD version the small bush fails but sometimes no quicker than the larger one toward the front. I have to find time to see if the poly-bushes for a FWD version is interchangeable. Not ideal as the poly-bushes do (as per charleskennedy23) make the engine/trans transfer far more vibration to the rest of the car, but in this case that may have to be the way as there is no other option currently.

Neil.