I have an 1996 SE with 241,000 miles on it. I've read all the forums and tech info on the UIM issue. I haven't had a chance to really clean off the engine but I can see a coolant leak around the LIM. My question is that my UIM has a date stamp of February 8, 2002. Should I replace this one with the APN unit or how could I tell if this is the Dorman unit? I plan to do the regular maintenance for economy (filters, plugs, wires, posn1 o2 sensor, 180 thermo, clean TB, the Dex is gone, only running green glycol etc.) and didn't want to do too much $$$ at once if I didn't need to. The car runs great. I haven't drained the oil yet to see if there is coolant in it. Also, if I do replace the LIM, UIM, etc. how much time should I allow? Two full days?

Thanks. I run the risk if I sleeve it myself that the UIM is not warped correct?

How do I contact Bob? I did a google search but couldn't locate him.

RE: the LIM. Yep I did my reading homework and was just going to clean and replace with the new Alum GM gaskets and elbow.

Common sense tells me that I shouldn't do a tuneup until I take care of the leaks? Otherwise I'll have to do that again right?

How much time to replace the LIM gasket and UIM provided I have all my parts in-hand before disassembly?

First off, I would be surprised if it were a Dorman, though it'* possible. Since you have to remove it anyway to replace those bad LIM gaskets, you can plan on one of a few less expensive options if cost is a big factor.

1) Pull the UIM and see if you have a sleeved UIM already (Again, I think it unlikely, but possible). This is the cheapest route, but also the most costly from a time perspective. If it'* OEM, then you will have to either sleeve it yourself or wait while a new APN/Dorman kit shows up in the mail.

2) You can contact billbuttermore (BC Member) and see if he'll sell you a sleeve kit for your existing UIM. This is pretty inexpensive, but again takes the time you'll need to sleeve it yourself after removing and cleaning it up.

3) Next up the cost list is to buy a rebuilt (pre-sleeved) used UIM from Bob Dillon (another BC Member) and have that ready to swap in upon removal.

OK, so that'* that. Now on to the LIM. You DO know that you should not have to replace the whole LIM, right? Only the LIM gaskets should require replacement unless yours is too severely ptted to reuse. I don't know if I've seen anyone here who was unable to reuse their LIM due to pitting. Is it fair to assume that you've already read the TECHINFO article on this and that you know that you should buy the aluminum-framed LIM gaskets and a new coolant elbow?

Lastly, you should plan on about 5 hours to do the complete swap, more or less depending on your personal mechanical ability and familiarity. I would suggest you carve out two days for just-in-case, since you don't know what you're dealing with yet and to allow for the appearance of Murphy.

I don't know what the flippin' flippity happened, buut somehow, while I was trying to edit my post to provide more info to you, it moved my post after yours...lol...silly computer and php...

Anyway, I already added my guesstimate on the time you'll need in my post above.

And yes, you do run a risk of having a warped UIM, but that would likely already have manifested itself, IMO.

Bob Dillon is a member here and you would do better by a search using BC'* search function. Anyway, here'* his profile: Bob Dillon
As to the tune up stuff, it'* easier to do the O2, plugs, and wires while you are doing the other work on it, but I myself might wait in the O2 and plugs until after the UIM and LIM work is completed, just in case you risk the fouling of those from the possible burn-off you'd get from coolant still where it shouldn't be.

I'd probably plan on the TB cleaning and thermostat replacement at the same time.

Thanks. Two final questions: IMO?

And, what have I been reading about drilled thermostats? Is that just for the proper filling or some other reason?

Lol! IMO = In My Opinion.

The drilled thermostat serves two purposes, but one main advantage is that it helps to keep from getting an air bubble when draining and re-filling the coolant system. Our cars can sometimes be rather finicky and will retain aan air bubble in the thermostat area. Here'* a nice TECHINFO article on the coolant fill procedure:

Now I get the drift that you're no newbie when it comes to working on your cars, so I included that only FYI (for your info...lol) and not to insult your intelligence or anything.

Sorry I overlooked the time recommendation on your previous post. I'm not offended and appreciate the help.

Do you know of a place where I can get my hands on a used set of factory service manuals? I tried to do some searches but could only find new stuff for $135. I mostly know what I'm doing but it'* nice to have a picture reference to something you can't identify when it'* right under your nose. I've used the Haynes manuals in the past but not very much as they only give an overview or assume you know exactly where the coolant elbow is located. If I know what it looks like I can remove it, it'* finding it under everything else is a little challenging. I saw one place that recommended alldata but I've never used it. Thoughts?

For the UIM and LIM gasket replacement you shouldn't need a FSM. Most members who have done this job have been successful without the aid of a FSM.

My suggestion is picking up a Chilton'* manual. They're far superior to the Haynes - especially when used as a point of reference for this job.

I agree. It'* Chilton'* No 28200 that you need. Anything else you run into on this work not addressed by the Chilton'* manual can be answered by lots of folks here on BC. Collective expertise and practical experience is DEEP on this subject.