AGH! Intake Manifold!

[Bonnefied_GM]

Hello, not sure where to start.

I got on this forum probably back in January after buying a '98 SE with 145k on the odometer. Well, it's at the shop now after sitting for over 2 months due to a jammed ignition lock cylinder (will require new keys and everything).

Well, although they'll replace the lock cylinder and keys AND do a transmission service for me (the fluid was getting dirty, which I neglected to check before), those are the least of my worries. I told them to do a once-over on the car since it leaks oil. They told me that the intake manifold is leaking coolant, but externally at the moment, having found coolant on the serpentine belt, hence why it was a tad squeaky when I first got it. I already read the Tech Info article on the replacement of these, but since I'll be having the work done by a third party and due to the plethora of details in the article, I wanted to know bullet points for what I should mention to the shop before they do my work (coolant, gaskets, etc). I know everyone here seems to push for the "mixes with any color" coolant, but what are the other details I should make sure the shop complies with, or are they even a necessity?

I consider myself a self-teaching-mechanic-in-training, but at this point in time, I do not feel comfortable tackling this issue, being well-aware of many of the things involved aftering reading the articles thoroughly.

If it helps, here are some details (1998 SE)

-145k miles

-oil was just changed by me including filter

-before the ignition locked up, the engine and tranny drove and performed flawlessly without abnormal sounds.

-the UIM has a manufacture date of May 2003 so it WAS replaced at some point in the past

-spark plugs, wires are new

-valve cover gaskets recently replaced, including new grommets

So like I said, just tell me what I should tell the shop to use/watch for. They are a rather large shop and have grown bigger in recent years, so I'm sure they're doing something right, lol (granted, they're always busy and taking lots of calls). I've been going to them for many years and they seem to do fine.

Estimate (labor and parts) totaled out to a hefty $781.35. I know I could have chosen a cheaper route or tried doing it myself, but that's my business (parts included the UIM and LIM manifolds/gaskets, serpentine belt, coolant, oil and filter)

[Bonnefied_GM]

Oh, and it DOES have the orange Dexcool in it.

[00Beast]

I guess the one thing I can think if is to make sure they replace the plastic coolant elbow from the LIM to the tensioner bracket. Some ppl try to re-use them and they always end up leaking.

[Bonnefied_GM]

Okay, noted What about the coolant? Why the "mixes with any" over the Dexcool?

[00Beast]

Dex-cool is just crap. If they do a thorough flush, regular green could be OK, but if it mixes with any dex it will sludge up like none other. Mixes with Any is fine for mixing w/ Dex.

[olblueeyesbonne]

Dex Cool EATS plastic and aluminum. You have plastic gaskets no doubt, and your LIM is aluminum.

[Bonnefied_GM]

I'm thinking of talking to a friend of mine who is a former mechanic and can do this work much more reliably than me, therefore saving me lots of money.

So, what I'm picking up from reading is:

1) make sure to replace the coolant elbows
2) use Prestone Long-Life "mixes with any" coolant after a flush
3) what are the part numbers for the recommended Manifolds/gaskets? Would I even be able to sneak an aftermarket ported lower intake manifold in without any trouble?

[willwren]

Your manifold is most likely the GM 'improved design' which is just as bad as the original, and can fail in as little as a year or two (we've already seen this happen a few times). APN and Dorman are the only reliable intake manifolds on the market. Make sure you use one of them, the aluminum-framed LIM gaskets, and do a proper FLUSH of the system to remove all Dex-Cool.

www.dex-cool.net

[Bonnefied_GM]

Yeah, I read that Dexcool article and that was some pretty interesting, if not compelling evidence. I'll make sure to relay this information over to whoever does the work. If a shop did it, is it likely they would follow such recommendations by default or do they use the crap that should be avoided?

[willwren]

Buy your parts and take them with the car. That's the safe bet. You also get better pricing that way.

[Bonnefied_GM]

So, I'm going to start calling around and getting some prices. I plan to buy the parts and find someone willing to use them. That being said, what about headgaskets? I never hear those mentioned much about 3800's and the shop didn't mention them either, so think I'm safe leaving them be or should I pay a little extra cash since the motor will be half-diassembled anyway and have them replaced? If so, which gaskets should I have used?

[willwren]

Don't touch the head gaskets. They're good for over 500k, and you can induce more problems by replacing them than you can by leaving them. Since 2002 when this Forum was created, and well over 15,000 cars, we haven't seen a single documented case of head gasket failure EXCEPT in one case of extreme over-boosting, one case of severe over-heating abuse, and one case of replacement errors on the part of the car owner. Those are the only 3 I can think of.

[bill buttermore]

If you are buying the parts yourself, the APN UIM is a much better deal than the Dorman. Unless they have changed it recently, the Dorman costs more but does NOT include a heat shield in the failure prone EGR passage. APN is the better choice. Here is the link for the APN manifold:

http://www.ineedparts.com/auto-parts/in ... 17806.html

Whether you choose Dorman or APN, make certain the mechanic installs the reduced diameter stovepipe that will come with either product.

Unless your LIM is badly pitted or warped (this can be easily checked when it is removed) there should be no need to buy a new one.

[Bonnefied_GM]

Thank you very much for the link Bill. I read elsewhere that the APN comes recommended over the Dorman. Speaking of which, is it only available online or can I find one at any local auto parts store?

Also, thanks for the heads up on the headgaskets Will. It's rather refreshing to hear those should never be a problem in the midst of this gasket crap, lol.

Unless your LIM is badly pitted or warped (this can be easily checked when it is removed) there should be no need to buy a new one.

Thanks. The only reason I considered getting one online was because I saw one being sold at some site that was ported and figured "eh, what the hell? Gonna have everything taken apart, might as well thrown in a modification"

[00Beast]

AFAIK, the APN kit is only available through that site.

Who is the vendor selling the Ported LIM's? It is a worthwhile mod.

[Bonnefied_GM]

There's a site called Milzy Motorsports. They seem to be a performance parts site for GM FWD cars, according to the tagline at the top of the homepage.

Here's the link to the ported manifold:
http://www.milzymotorsports.com/miva/me ... ode=L36LIM

[00Beast]

I'd avoid a gasket-matched manifold. You want to match it to the ports in the heads, not the gasket. willwren has an excellent CAD drawing of why.

[bill buttermore]

AFAIK, the APN kit is only available through that site.

Yep, I think that's right. Would sure be nice if they were available locally; that's why people pay more for the Dorman, because they don't want to wait for shipping. In this case, if you can afford to be patient, you not only save money but also get a better product.

[Bonnefied_GM]

Think I should just keep it cheaper and simpler and leave it stock? It's not a huge issue for me anyway as far as mods go. I generally just do intake and exhaust on my cars, tint windows, some other tint here and there and keep them clean and maintained I find my cars plenty comfortable and powerful to drive as they are.

Eh, I'll leave it. I'll just buy the APN kit and aluminum gaskets.

[Bonnefied_GM]

AFAIK, the APN kit is only available through that site.

Yep, I think that's right. Would sure be nice if they were available locally; that's why people pay more for the Dorman, because they don't want to wait for shipping. In this case, if you can afford to be patient, you not only save money but also get a better product.

My thinking was, since I can find ways to get around without a car in tight situations, I'll just do that and leave it parked in the garage once I get it back from the shop that's doing the ignition work. In the meantime, I'll gather the parts and arrange a shop to do the work. That will also involve waiting for the APN kit