Trebor

Hi:

I bought a new o ring for the CPS. I can not get the bolt out that holds the CPS in place. A few questions for anyone who has done this:

1. Bolt size 8mm yes or no

2. Did you remove it from the top (sticking arm down passenger side next to power steering resevoir)?

or

3. Did you remove it with the car up on ramps from beneath the car?

4. If yes, did you have to remove crossmember?

5. Did you use an open end wrench or socket?

Any other tips greatly appreciated

trebor

96GS#007

The bolt is 8mm

You remove it from below

Remove the two (1/side) 18mm nuts that secure each motor mount stud to the diagonal cross brace.

Jack the engine up ~1"

You should now have enough room to remove the bolt using an open end wrench.

MikeC4

Jim,
When you jack the engine, what do you use to "spread" the load, 2X4 or 4X8 piece of wood ?

Also, do you Jack at the oil pan or some other location. I want to replace my son's balancer/pully, and, on an LT4 it I cannot get the balancer/pully out without raising the engine somewhat. LT1's don't have this problem, as I think the balancer/pully is a bit smaller so it doesn't have the intereference problem with the front crossmember like the LT4....

Thanks !
MikeC4

96GS#007

I use a block of wood like you mention above...8" x 8" x 2" thick. I put it under either the oil pan or the transmission. Just depends what else I'm trying to mess with under there at the time.

LT4AUTOXER

I was able to pull it out by reaching down from above. You have to pretty much go by feel, but it was otherwise pretty straight forward.

Trebor

I believe I can remove it from above too. I can reach and pull the plug off the CPS from above with no problem. I can feel the top of the 8mm bolt with my fingers. I bent the shaft of a socket driver to 45 degrees and put the 8mm socket on it. I hooked up a couple of times with the top of the bolt head but could not generate enough torque to break the bolt loose. I am thinking of buying a flex driver.

What type of wrench did you use?? Any tips appreciated.

thanks,

trebor

MikeC4

Trebor, are you saying that you can do this without raising the engine from the motor mounts ??

-Mike

96GS#007

Been there, done that, have the trophy. Jack the car, lift the engine an inch and in 5 minutes from below you're done...and you can see what you're doing.

Trebor

Yes...using an led flash light I can see the CPS at the bottom of the timing cover. I can easily reach in and unplug the wire from the sensor. And as I mentioned, I can touch the 8mm bolt (can't see it) and I was able to get the 8mm socket over the head of the bolt but it was too tight a space to maintain enough torque to spin the bolt out and kept slipping off with the tool I was using. WIth a long thin flexible socket driver, I believe it's do-able without lifting the motor. I will let you know once I find he right tool.

trebor

96GS#007

You are making this waaaaaaaaaaaaaaaaaaaaaaaaaaaay too hard. On the later C4s, they use hydraulic engine mounts. Each mount has a stud that passes thru the diagonal brace that runs from the frame rail to the main crossmember under the engine. On that stud is literally 1 nut (per side) that you loosen. The nut is 18mm.

If you took the car to the dealer, to a shop, or even a half-a$$ed shade tree mechanic, they'd have it done exactly as I've spelled out in 5 minutes.

But hey, whatever....

MikeC4

Jim,

I will be lifting the motor. I think you just pointed out a critical step in your last post, which is to "loosen" the 18mm motor mount nut and not remove it. I was concerned that if I removed the nut and raised the engine to high, the motor mount bolts would go through the mounting hole completely and then get mis-aligned upon lowering the engine. This was my big worry. I messed with C3 motor mounts in the past, and I always had problems getting good clean alignment.

EDIT:
Jim, I just re-read your earlier posts and you said "remove" the motor mount nuts ???

Remove or Lossen ????????

Thanks for the great advice!
Mike

96GS#007

Either one works. If you lift the engine so high that the studs are no longer aligned with the holes you'll have bigger issues...namely you'll be jamming the back of the engine into the firewall. If anything, just leave the nuts on the last couple threads of each stud and that'll keep you safe. Everyone gets nervous about lifting the engine, but trust me there's no rocket science involved with this

96GS#007

Here are some pics....





Motor mount stud and 18mm nut...