2001 C70 Convertible 2.4 liter low growling noise

janders99 · Post by **janders99** » 24 Oct 2013, 20:11

Apologize if this is the wrong place to post or if I have not found the answer already posted. I have 211,500 miles and within the past 5,000 a loud, low-frequency growling noise has happened. Appears not to be in reverse gear. Occurs in all forward gears and in neutral. The resulting vibration is more than annoying and getting worse. I believe -- mostly a hunch -- that it is the transmission (refurbished one that replaced new transmission at 88,000 miles). My mechanic commented offhandedly that it "sounded like a catalytic converter. Either of these would be a death sentence but I would like to keep the car. Any ideas on diagnosis or further steps? I do not have lights nor have I pulled codes.

Post by **jblackburn** » 25 Oct 2013, 09:48

Does it increase with speed or RPM?

Does it change if you swerve HARD from side to side @ 45 MPH?

lars martinson · Post by **lars martinson** » 25 Oct 2013, 21:13

It sounds like the lower front engine mount has failed. When it fails, the motor rests on the sub-frame and gives off some pretty intense vibrations at idle and growls loud under acceleration. Pretty easy fix... about $40 and 30-45 min to replace. It would be worth it to take a look before you buy any parts. The mount is located behind the front passenger wheel. You can find threads on replacement. Also, I wouldn't let it go too long... I waited on my AWD and it destroyed a brand new driveshaft and both front axle boots...

janders99 · Post by **janders99** » 02 Apr 2014, 14:25

You are right. Finally had my mechanic confirm motor mount(s?). On one hand I'm relieved b/c all of the symptoms are accounted for. On the other hand, my mechanic says "four mounts, $900" which I can't afford. I can see that the top mount does *not* need to be replaced -- it was already replaced at about 130,000 (212,000 now). So I'm looking at the "front" mount (by the passenger side front wheel) and the two hydraulic mounts. Should these be done in any particular sequence? All at once? Also (sorry for yelling) COULD WE PLEASE HAVE COMMON TERMINOLOGY FOR THE MOUNTS?! It is very hard to identify even which ones go where when shopping. Is there a mounts "package" that contains multiple quality parts and perhaps bushings, etc. where they might be needed?

Post by **erikv11** » 02 Apr 2014, 14:39

Sequence of replacement

(1) top mount, on the torque bushing. If yours was last done at 130k it is probably wasted again at 210k. Post a pic here if you want a second opinion.

(2) front mount, under the crank pulley. It is called front because it is on the front of the engine (which is on the side of the car, alas ...).

(3) the transmission torque mount, and the firewall side of the top mount, are the other common mount failures.

(4) it is rare for the hydraulic mounts to fail, although we are starting to see that now. These don't fail catastrophically like the others, which just break, rather these start sagging.

I would replace 1 and 2 and re-evaluate. There is no advantage to doing 3 and 4 at the same time. 1 and 2 are fairly easy DIY jobs, FWIW; you could do those two for less than $90 in parts. And probably end up with better quality parts than your mechanic would put in.

Don't buy cheap rubber engine mounts, they will fall apart right away.

EDIT: my comments apply to the cars relevant to this forum, i.e. up to a 2000. I didn't realize you were asking about a 2001. It is likely the same or similar but no guarantees.

janders99 · Post by **janders99** » 02 Apr 2014, 17:36

Thanks for the offer, erikv11. Here are two pics of the top mount, in which I tried to show as much of the rubber interior piece as possible and any horizontal cracks...

janders99 · Post by **janders99** » 02 Apr 2014, 17:46

Posted the *same picture* twice earlier...here is the actual second picture

janders99 · Post by **janders99** » 02 Apr 2014, 17:57

Also, erikv11, I'm aware of the apparent "too young for this topic" issue with my car but this appears to be the most relevant MVS section for me. Plus almost all parts for my car list older years in the fitment notes. If there are lots of '01 C70 posts elsewhere, I'd like to know about them. Thanks again. janders99

Mod note...correct forum for C70 through 2004

Post by **erikv11** » 02 Apr 2014, 22:15

I don't really know about the other forum sections but sure, we can give your questions a shot. There are other people who probably know your car, I just don't.

Well I can't tell for sure but that top mount does look at least OK, it isn't trashed. Try shaking the engine by hand and check for motion, or revving it up and see if it leans in the mount. If not, maybe it is still good.

Post by **abscate** » 03 Apr 2014, 05:54

This forum covers the C70 through 2004

Welcome!!!!