New Logs for Old (Page 1/2)
Notorio AUG 09, 09:27 PM
Finally addressing my start-up clouds with new valve stem seals and decided to upgrade to some ported exhaust logs at the same time. Unfortunately, I can't seem to get a wrench on the #6 cylinder lower exhaust bolt (firewall, passenger side). This is an 88GT 5-sp. I've removed the bolts from the AC compressor and dropped it down and away from the bolt about an inch. Do I have to remove the coolant pipe passing through here as well?? The trunk lid is off, the upper and mid intakes are off, valve covers still on. I've tried approaching from every direction and the closest I can get to the nut is a box-end wrench reaching down from the top, but with no leverage and almost no space to move. Is there an easier way I am missing ???
thesameguy AUG 10, 05:22 AM
When I did this last year the only thing I did was flop the AC compressor away - no deck lid removal, no intake removal, no coolant pipe removal. My access was a combo of above & below depending on the specific nut, but no disassembly beyond removing the belt so I could swing the compressor away. My recollection is that I used a combination of ratcheting box wrenches and regular sockets on a flex-head ratchet. It's possible I used some Gearwrench hollow sockets, but I think that was only for reassembly as I made some adjustments along the way. I do remember very specifically being impressed with the access from below - on the firewall side, working from above was a PITA.
Notorio AUG 10, 10:32 AM

quote
Originally posted by thesameguy:

When I did this last year the only thing I did was flop the AC compressor away - no deck lid removal, no intake removal, no coolant pipe removal. My access was a combo of above & below depending on the specific nut, but no disassembly beyond removing the belt so I could swing the compressor away. My recollection is that I used a combination of ratcheting box wrenches and regular sockets on a flex-head ratchet. It's possible I used some Gearwrench hollow sockets, but I think that was only for reassembly as I made some adjustments along the way. I do remember very specifically being impressed with the access from below - on the firewall side, working from above was a PITA.



Ah, ratcheting box wrench ... that makes sense from what I've tried (my 3/8" ratchet head just can't get in there). I'll zip down to O'Reilly's to get one, which I could use anyway. Thanks!
thesameguy AUG 10, 11:08 AM
Make sure you get one with a lot of teeth. Some of the cheap ones need a substantial swing in order to ratchet, whereas good ones can move in just a few degrees. I'm not sure if that's important in this application, but having ratcheting wrenches that don't always work sucks.

If you wanna expand your tool box, these are not a bad deal:

https://www.amazon.com/TEKT...ing+wrench+set&psc=1

[This message has been edited by thesameguy (edited 08-10-2018).]

Notorio AUG 10, 03:37 PM
So here is what I had to do after completely dropping the compressor ...

Happily, 13 mm and 1/2" are interchangeable so I had what I needed after all. First, I used a 12" long swivel-head 3/8" drive extension that allows a socket to pivot a few degrees off axis. With this I loosened the stud then backed it out with the 1/4" drive socket. Why did I use the swivel and not a u-joint?? The 3/8" u-joint wouldn't fit between the (!!$&%&*!!) compressor mounting bracket with a socket attached. Even the 1/4" drive u-joint would only make a few turns until it backed into the wretched bracket.

Note on the other two tools shown here: the box-end ratchet wouldn't fit onto the nut because the diameter of the wrench head was a little bit too large. By way of contrast, the 13mm box-end wrench DOES fit onto the nut but there was very little movement and no leverage between the coolant pipe and the log. Approaching instead from below was blocked by the oil pressure sensor feed pipe. If the wrench was shorter that would have worked (or I could have pulled that oil pressure feed pipe.) Thinking about it further now perhaps a Crow's foot wrench might have gotten in there.





All's well that ends well. For those of you who were able to get #6 off without removing the compressor I take my hat off to you.
Patrick AUG 10, 03:53 PM

Be ever so grateful you weren't dealing with a broken exhaust manifold bolt in that same location. I still break into a cold sweat thinking about what I had to do years ago tackling that task on my '86 GT. It's was horrible!
Notorio AUG 12, 08:40 PM
I was (and am) grateful, in fact the #6 stud shearing off was running through my mind almost the whole time. To tell the truth I was very frustrated that a job done by thousand's of mechanics and car owners for the last 30 yrs was giving me such a hard time. At the end I had a vision flash before my eyes of Pontiac Engineers validating their manifold R&R procedure using their standard set of tools and making no allowance for someone who might have a slightly larger wrench, etc. (thus, 'it worked for me ...')

But to look toward the future, I was tossing and turning in bed last night thinking, at this point, I might as well pull the heads and get a real valve job done rather than just replace the stem seals. But if I'm going to do that (at 98k miles) shouldn't I also do a timing chain and a water pump?? What do you think? And what else should I be considering?
Notorio AUG 15, 12:16 AM
Finally got a chance to examine the old manifolds today and was surprised to find that the end flange on the odd side was cracked all around the inner weld and almost ready to fall off. The end flange of the even side actually DID fall off, right into my hand!

Five of the six ports had powdery black residue whereas one (shown here) had powdery white. I will have to check the plugs tomorrow to see if they tell the same story



Patrick AUG 15, 01:09 AM

quote
Originally posted by Notorio:

Finally got a chance to examine the old manifolds today and was surprised to find that the end flange on the odd side was cracked all around the inner weld and almost ready to fall off. The end flange of the even side actually DID fall off, right into my hand!



That sucks. Are you going to have them re-welded... or replace them?

[EDIT] I re-read your first post.


quote
Originally posted by Notorio:

...decided to upgrade to some ported exhaust logs at the same time.


[This message has been edited by Patrick (edited 08-15-2018).]

thesameguy AUG 15, 02:44 PM
When I did mine, I had no issues with any of the nuts on the head, but the collar at the y-pipe in back was a little stuck. I gave it a good yank and the entire manifold unwrapped - I literally ripped the end of the manifold off:

This images is larger than 153600 bytes. Click to view.

The manifold were crap to start with and couldn't even survive a couple decades in California. Definitely a Top 5 Worst Component on a Fiero.

Nobody around here would tackle the repair. I ended up waiting a couple months for WCF to crank a couple new ones out. It was frustrating but worth it. At least Tehachapi isn't as far from you as it is from me!