: Rough Idling Catera Please Help



jason428sc
12-12-10, 09:06 PM
Hi guys,

I just bought a 2000 Catera that needed a new head gasket. I figured I could have a nice car for a good price it I did a little work to it. So after I replaced the head gaskets & plugs the car idles rough at 500 RPMs. It only runs rough at idle. It drives and rides perfect. I have checked for vacuum leaks and cleaned the throttle body, but still idles rough. Any body have any other ideas?

Thanks.

hgqguy
12-12-10, 10:05 PM
mine intermittently vibrates at 500rpms also. I try to ignore it cause it drives fine, and has had a ton of work. I have come to the conclution that the motor mounts have lost some cusion.

USEDCAT
12-13-10, 09:47 AM
Hi guys,

I just bought a 2000 Catera that needed a new head gasket. I figured I could have a nice car for a good price it I did a little work to it. So after I replaced the head gaskets & plugs the car idles rough at 500 RPMs. It only runs rough at idle. It drives and rides perfect. I have checked for vacuum leaks and cleaned the throttle body, but still idles rough. Any body have any other ideas?

Thanks.
Did you clean the breathers all around? The breathers are heavily involved at idle. You need to clean all and very well as well as replace the o-rings (tiny things) and I think that is about all you can do except for making sure MAF is also good.

Cheers.

jason428sc
12-13-10, 03:48 PM
Thanks for the advice. Are the engine mounts a common problem for the Catera? And where are the o-rings located Usedcat is talking about?

USEDCAT
12-13-10, 09:34 PM
Thanks for the advice. Are the engine mounts a common problem for the Catera? And where are the o-rings located Usedcat is talking about?
I have a cut and paste saved for my reference but it is about 5.6 MB. Let me know if you want a copy and I will be happy to share. Most of it is from Omegaownersforum. The following can suffice as starters,

http://www.omegaowners.com/forum/YaBB.pl?num=1285583967

Cheers.

jason428sc
12-13-10, 10:26 PM
Thanks Usedcat, but I can not open the link. Is there another one?:hmm:

USEDCAT
12-13-10, 10:32 PM
Thanks Usedcat, but I can not open the link. Is there another one?:hmm:
I am a member there and the membership is free and they don't have any ads. I did not login but was able to read the guide I don't know why you can't. As I wrote I did save it for my self on my PC and be happy to share but you will find so much more at Omegaowners. Omegas are a base for the Cadillacs that were sold in North America and built in Germany (old Opel plants).

May be try the following and look under Maintenance Guides in the main page. It is possible they don't give direct access to single pages/posts,

http://www.omegaowners.com/forum/YaBB.pl


Let me know if I can help further.

hgqguy
12-15-10, 05:17 PM
Im not saying the motor mounts are a problem. I am just assuming they could be the cause of the vibration in mine.
BTW rockauto.com has refurbished acdelco MAF here is link. 55.oo after you return your core!
http://www.rockauto.com/catalog/raframecatalog.php?carcode=1428713&parttype=5128&partkey=1302469&a=FRc1428713k1302469-6493351

verify the vin is R i know the 01-03 l300 is the same, this was for 04-05 l300 and $130price. with $32 core refunded here is link for $100 one
http://www.partsgeek.com/gbproducts/MC/4848-07005591.html?utm_source=google&utm_medium=ff&utm_term=2001-2003%20Saturn%20L300%20Air%20Mass%20Sensor%20A1%20 Cardone%2001-03%20Saturn%20Air%20Mass%20Sensor%2002%202002&utm_content=MC&utm_campaign=PartsGeek%20Google%20Base

investor74
12-15-10, 10:26 PM
I've had my Catera for 14 years and have become a fan of "snake oil" solutions.

Last summer, I had a check engine light that pointed to an O2 Sensor. With inspection coming up, I ordered an O2 sensor but also tried STP gas treatment just in case the O2 sensor didn't arrive. After a couple of fillups with the STP, the check engine went out and stayed out for the last 2 months. I returned the O2 sensor.

The gas treatment also smoothed out the engine at idle. I had previously had occasional roughness at idle. Now it is smooth as silk at all speeds. I think the gas treatment cleans the injectors. BTW, the plugs have never been changed on the car (14 years, 111 K )

jason428sc
12-16-10, 10:19 AM
Thanks I'll give the gas treatment a try. I haven't had any luck with anything else. Engine mounts are fine. I cleaned all the idle sensor lines, checked for vacuum leaks. Not sure where else to look. I'll let you know if that works. Thanks.