: Mystery Rubber Hose by Firewall -- 2000 Catera



FM-IN-MI
10-28-06, 02:22 PM
Hello all,

This weekend we tackled the valve cover replacement project on my son's car after reading all the suggestions on this forum. It went well, although we went very slowly, marking all the tubes, putting parts on separate pieces of 3' by 3' paper w/ exact descriptions and taking pictures all the way through. It took us 6 hours, including cleaning up all the parts thoroughly and also doing a tune up (new plugs -- used the Bosch +2 Platnium instead of the $18/each GM Bosch 3 tip).

Did you know that the Catera can run on 3 cylinders if you forget to connect one of the coil connectors (which fires 3 spark plugs)? OK, so we make one error...

We do have one mystery however -- as we took the air plenum off, we found a ~1/2 inch thick-walled rubber hose behind it. On the intake plenum there were 4 hoses; this was a 5th that had no visible connector anywhere! The book does not show it. It goes down the firewall to some place above the transmission but we could not see to where. It appears to go to something that is 'sealed' -- we blew into the hose slightly and felt backpressure, then air release. Putting a slight suction on it gave the same impression -- a closed ????.

Anyone have any idea what it might be and where it should go? Could it be a vent for the transmission? It seems strange that Cadillac would not do a better termination job.

Thanks for your help.

Frank in Michigan

contourbs
10-28-06, 03:33 PM
im sure its the transmission vent tube, where it connects to i dont know or even if if does connect anywhere

klm
10-28-06, 06:16 PM
Don't worry. It's just the breather for the tranny. Just make sure that it is stapped high up and allow it to point back down.
I spent hours trying to find a reference to it in the service manual, but it's not in there.

bwmjj
10-29-06, 12:36 AM
Thanks a bunch. My next question is --- if I receive a p305 code showing the misfire on No. 5 plug, would that necessitate replacement of the coil pack?

contourbs
10-29-06, 08:14 AM
you might wanna start with wires due to the oil messing them up from the valve cover leaking

donnie
10-29-06, 08:49 AM
Hello,
I've got to replace my valve cover gaskets as well.
Questions:
1. Do I have to pull the intake and therfore need a lower intake gasket?
2. I've read about a new and improved heat exchanger. Should that be replaced while I'm doing the cover gasket? So far no problems with the existing exchanger. Anybody got details on the improved exchanger?
3. Anything else I need to look out for?
Thanks for the help

FM-IN-MI
10-29-06, 10:02 AM
Hello,
I've got to replace my valve cover gaskets as well.
Questions:
1. Do I have to pull the intake and therfore need a lower intake gasket?
2. I've read about a new and improved heat exchanger. Should that be replaced while I'm doing the cover gasket? So far no problems with the existing exchanger. Anybody got details on the improved exchanger?
3. Anything else I need to look out for?
Thanks for the help

We just did this job as mentioned above and did pull the intake manifold. We did NOT have to replace the plenum or intake gaskets -- they were fine. We did however buy them in advance (from RockAuto) just in case. We are returning them this week as they have a very good return policy. They also had the lowest price for the valve cover gaskets. You should read the other postings for valve covers as this topic was more for connections, not gasket replacement.

As for the heat exchanger, I would leave it alone if there is no problem. It does take a fair amount of time to get to but you may open up a can of worms if you try to replace it. If it is not broke, don't fix it was my uncle's motto (life-long mechanic). I would however suggest you change your plugs if over 75K as you will have the perfect opportunity to do this and it will only take an extra 15 minutes at this point. Make sure to wipe and blow out the 'well' before removing the plugs completely -- we found a lot of crap (particulate, oil) in there that could fall into the cylinder or prevent the new plugs from seating properly.

Good luck.

Frank in Michigan

donnie
10-29-06, 01:20 PM
Thanks, I did read other post but yours was most helpful. Its' still not clear however about the intake;you pulled it but was that required? Also, did you use any gasket sealer. If so what type? I've already ordered FelPro gaskets from Advanced Auto Parts but they did cost a little more. $45.00
Thanks again

FM-IN-MI
10-30-06, 08:06 AM
Thanks, I did read other post but yours was most helpful. Its' still not clear however about the intake;you pulled it but was that required? Also, did you use any gasket sealer. If so what type? I've already ordered FelPro gaskets from Advanced Auto Parts but they did cost a little more. $45.00
Thanks again
We pulled the intake manifold for two reasons -- we wanted to see if there was oil / corrosion under there and because the service manual said you had to :-)

I went back and looked at the pictures we took. The vains of the intake stick out over covers. It would at least be very tight to remove the covers if possible. But I am guessing that if GM has it as a requirement to remove it, that has to be done...

I was surprised about the price at AAP - our store said $65! I didn't know there were store-to-store pricing differences.

Good luck with the project. I am sure you will do fire -- it was not that bad at all.

Frank in Michigan