2002 V70 T5 rough idle/engine shakes

dos_volvos · Post by **dos_volvos** » 13 Apr 2010, 23:00

Need help with a 2002 V70 T5 109,000 miles. Here's the problem - with the transmission in drive and the car not moving, the engine has a rough idle and rhythmic shake. The shaking is wave-like and the idle appears to be surging. The idle is 800 rpm with no fluctuations. When I shift to park the symptoms go away with idle remaining @ 800 rpm. If I shift back to drive and increase the idle to 1000 rpm, no rough idle or engine shakes. No diagnostic codes have appeared. The car runs great on street and freeway driving except when I have to stop and then the symptoms reappear. I noticed this condition awhile back but it was very slight, not as severe. The 90,000 mile service at the Volvo independent did not make any note of this condition on the work order. My wife said that it has gotten worse over the last two weeks. The most recent service has been a complete timing belt change @ 99,000 miles with your help at this great site. Here's what I've checked so far:

Timing - intake camshaft off 1/2 tooth

Engine mounts - top mount has a small separation. Will order from FCP. Front lower right near TB cover appears to be OK. Any other engine and/or transmission mounts I should check?

Vacuum leaks - sprayed carb cleaner @ fittings/elbows - no rise in rpm when sprayed thus no leaks?

I'll check spark plugs/wires and get some fuel injector cleaner tomorrow. Any help would be appreciated. Also, will need help with a 1998 S70 N/A front camshaft seal replacement but that's another story....thanks again.

dos_volvos

Post by **E170_Driver** » 14 Apr 2010, 06:04

About 20,000 miles ago I noticed some similar symptoms with my 2001 V70, especially when the car was put into reverse the engine would shake. I had the upper and two lower engine mounts replaced and VOILA, no more shaking. One of the lower engine mounts was completely collapsed due to an oil leak I had and the other was just worn.

Good Luck

Jan

Post by **djm850** » 14 Apr 2010, 06:12

If it's not a rough running issue with the motor itself, then I'd bet on the top mount. You might also want to check the "dog-bone" tanny mount on the bottom near the front, driver side. Remember, on the top mount the arm itself has a mount at the firewall too. Failure rate is prolly not as high as the larger mount at the motor, but if it is blown changing out the large one won't solve the issue entirely. It's best to check these mounts with another person so the car can be shifted in and out of gear to observe the mounts stretching. BUT BE CAREFULL as always (disclaimer). If you decide not to go back with the Volvo original on the large mount and opt for a solid elastomer type, you will notice more vibration over the original.

dos_volvos · Post by **dos_volvos** » 14 Apr 2010, 16:13

Thanks E170_Driver and djm850. I'll take a look at the mounts when I get home and post the results.

dos_volvos · Post by **dos_volvos** » 16 Apr 2010, 16:43

Checked the dog-bone transmission mount and front lower engine mount as per djm850. Everything looked normal but replaced the top mount since the rubber was separating with an OEM from stealership...I was desperate and couldn't wait for a FCP order. No change in symptoms. What I did notice when the wife put it in drive was the engine twisting with the transmission engaged in the drive and reverse. Also, the strut bar mount was twisting allowing the engine to move. The new upper engine mount is attached to this strut bar. There was a definite clunking and roughness when shifting the transmission. I'm thinking new strut bar mounts, front lower engine mount and dog-bone transmission mount. The last two items only because I might as well put new mounts all at the same time and it looks relatively easy to install. Any comments....

Post by **E170_Driver** » 19 Apr 2010, 09:05

zwei_volvos,

your statement of the engine twisting when engaging into drive makes me think that there might be a more severe problem with the transmission (not trying to scare you). I would check the ATF level next time you are under the hood; make sure the level lines up with the HOT or COLD marks as appropriate. When I did my Drain and Fill of the automatic transmission fluid I noticed a harsh engagement (twisting of the engine) from P to R the first time I engaged the transmission and blamed this at a lack of fluid in the appropriate places within the transmission (since I drained a bunch out and filled it back up, therefore the ATF had no chance of being circulated yet). Just another item to eliminate in your endeavour to fix your car.

Good Luck,

Jan

Post by **djm850** » 21 Apr 2010, 09:09

You may as well check the three main mounts that support the engine. There's a small mount on the passenger side right near the crank pulley. When it fails it drops down allowing the whole right side of the engine for sink a bit (there's pics of this on Bay13 and maybe here too). Then you've got the two large hydraulic filled mounts, both toward the drivers side of the car, one back near the stearing rack and the other up near the radiator. Visible sign of failure is fluid leaking out. If these fail you might get fore/aft rocking.

dos_volvos · Post by **dos_volvos** » 21 Apr 2010, 23:33

Checked the transmission fluid - level was about 1/2 quart low. Topped off with Toyota Type T IV. The fluid was brown so I'll undertake the "drain and replace" method after I receive the mounts from FCP. I had the transmission fluid replaced @ 77,000. I'll check the hydraulic mounts as per djm850. I should be getting the FCP shipment soon so I'll post. Thanks again djm850 for the reply.

dos_volvos · Post by **dos_volvos** » 01 May 2010, 14:27

To close the loop on this one..took the V70 to a new Volvo independent to check out the symptoms. I exhausted all avenues and decided to go with a pro on this one. I did not install the dog-bone transmission torque mount or front lower mount near the crankshaft. I decided to wait on those until after the diagnosis. The mechanic asked if the car had the ECM software upgrade which been had done previously awhile back. He concurred that it had an uneven idle and the engine was loping - his description of the rhythmic surge of the engine. He hooked up the computer and got an intake vacuum leak DTC. He wanted to do a smoke test and then clean out the throttle body. He found no vacuum leak, cleaned the throttle body and replaced a gasket. Lo and behold, she idles nice and smooth now. Initially on startup after the TB cleaning it was a rough idle but it smoothed out after everything settled in. Once again, a big thanks for the help and hopefully this can help someone out in the future.

alexk243 · Post by **alexk243** » 18 Feb 2013, 20:31

Do you know what gasket he replaced on the throttle body?