[thewubs]

Hello all,

Just picked up a 2000 Impala last week with the 3800 in it. I got a*good deal*on it and even aware of problems, picked it up. 210k miles, fresh oil change, fresh coolant + coolant flush, no signs of oil in coolant or vice versa. Zero smoke.*It was leaking a bit of coolant, and I had it checked out. I was told it was the thermostat housing, which was replaced. I asked them to check the intake manifold to be sure the leak wasn't coming from there, and was told it was not - in fact, the manifold at some point had been replaced by what appeared to be an aftermarket manifold - presumably including aftermarket gaskets. However, it's still leaking coolant. I have attached a photo with the circled area indicating where the coolant pools. There's no coolant underneath the*car*when parked, so I guess it just pools in the crevices. It has been kinda chilly up in Denver the last couple days, and the low coolant light has been intermittently coming on. I have topped it off with some coolant, and the light is still intermittet. Maybe cuz of the weather?

This is a photo I just took to show where the coolant pools.I did see some coolant residue ddown on the crossmember just now.

Any input is appreciated.

 

[thewubs]

I assume its the UIM, but its worth a shot

 

[thewubs]

I'm not trying to pad my post count or spam my own thread, but both the oil and coolant are still void of one another. The photo makes the coolant look very dark, but it's still pink under normal light. I might get the coolant changed over to non-dexcool soon

 

[thewubs]

I feared as much. Here's another photo - probably not much help but here goes. I can't get my phone down into where I really think the leak is coming from but this should give an idea at least.

The leak appears to be coming from where the plastic part of the manifold, throttle body, and lower portion of the intake meet. Had to heat it up and it decided to show tits time as opposed to me not seeing it last time I tried.

 

[thewubs]

Does anyone know the date codes for the intake manifold? Perhaps I'll luck out and it be one of the post-2003 replacements which AFAIK fixed the EGR tube melting, and it just end up being the throttle body gasket. Not holding my breath though

 

[thewubs]

Well, I found it. If looking from the front, down to the right of the engine right where my second photo is taken, right between the plastic manifold and the lower manifold (or heads?) It bleeds coolant like a stuck pig. still nothing internal a far as I can tell. No coolant in oil or vice versa, no white smoke. I won't be able to afford the repair for another week or so, ~100 miles of driving to and from work. Is it safe to drive till then, assuming it remains an external leak? I don't have a problem taking the bus for a week if there should be any fear of the leak turning internal. I have the coolant topped off, and the low coolant light has not popped on since I topped it off a few days ago. In my eyes, the leak is something that needs to be taken care of as soon as possible, but it is not an emergency at the moment given the fact that it appears to be fully external - that is my logic, PLEASE call me out on it being unsound thinking if that is the case! I don't want to blow this car up. I like it a lot.

I have no idea why I wasn't able to see it before, nor was the shop that fixed the thermostat, as it is VERY obvious. It might only be when the engine is cold? The shop that did the tstat said they had it running for an hour and it showed ZERO signs of a leak. I assume as the engine was warm there, as it was just now when I tried to record the video, and that would explain why they didn't see the leak after repairing it.

Gonna record a vid on my phone and see if that can help y'all very helpful folks help me. Thanks.

well, I just recorded a short video that I'll upload to youtube and link here (it'll do a better job of indicating where the leak is originating from than my photos) but when trying to replicate the leak on a WARM engine, I couldn't get it to do it. It did it on a relatively cold engine before I left work, and I will try to replicate it a bit later today when it cools back down. Confusing.

You can see a bit of coolant drizzling out of the manifold, but it was almost "shooting out" with much more force when I had my friend step on the gas. The important thing really though is being able to show WHERE the leak is coming from, which might help narrow it down a bit.

2000 Impala w/ 3.8L motor coolant leak location - YouTube

(ps - turn your volume down, I guess I was yelling at my phone :lol

 

[thewubs]

Grr...darn edit window, I don't mean to keep posting.

When my friend stepped on the gas at work, it appeared to me that the coolant was jetting out up out of the bolt connecting the UIM w/ the LIM right underneath the throttle body. It was only "shooting" out about 1/2" or so, if that makes any difference.

 

[thewubs]

I'm quite convinced my manifold is either cracked, or it is leaking through the gasket. With that being said, there's still no coolant in oil or vice versa. I found a really cool "shop" out here in Denver that works like a gym - you can get a membership or pay a daily flat rate to use their shop/tools for cars and just about anything else you can imagine. They have CNC milling machines, a lift, and a bunch of other stuff.

Anyway, is this a project that is reasonable to be done on your own with little mechanical experience? The guy I talked to at the shop says there's always someone there to help, and if I was there while he was there, he'd walk me through the tougher parts. That inspires confidence, but I'm still kind of iffy. I would, of course, have a set of printed copies and/or a repair manual to assist.

All my research points out that the re-torquing of the bolts to inch-lbs is the only part that requires any special tools (a torque wrench in in-lbs). Any guidance on that as well? Should I get the REVISED OEM parts? Or go aftermarket, e.g. Dorman intake + Felpro gaskets? I plan on getting everything - the manifold, gaskets, new bolts - just to be safe.

 

[thewubs]

They do have torque wrenches, but none that drop down to inch-lbs. Thanks for the vote of confidence, we'll see how it goes Thursday/Friday.

If I do find coolant in the engine, should I change the spark plugs too? If so, I might reconsider as I read the rears are a huge PITA.

 

[thewubs]

Seriously? It's a pretty standard tool to have. Maybe you can rent one from an auto parts store? If you do find coolant in the cylinders, yes you will need to replace the plugs. The back ones are a bit of a pain, but not that bad. If you unbolt the front engine mounts (dogbones), you can rock the engine forward for extra room.

Yeah, considering they have air tools, CNC mills/lathes, ect., I too was surprised when he said no. I specifically asked about in-lb torque wrenches and he said no, but they do have ft-lb wrenches. I am checking with the shops nearby and imagine I can find one, one way or another. Worst case scenario, I buy one and hang onto it, or unload it on craigslist. Either way, that's the least of my worries. I just am concerned about cracking open the engine and finding a can of worms.

I found a good series of videos, albeit on a 95 buick, showing the removal and reinstallation of both the upper and lower intake manifolds and gaskets. I'm really looking forward to this and feeling extremely confident about doing it myself and giving the bird to the shops that want my $$$ :lol:

 

[thewubs]

Also, regarding replacing the spark plugs, why is this a necessity if there is indeed coolant reaching the cylinders? Fouling on the plugs? It still runs like a top and smooth as all hell, which really is giving me hope that nothing is getting inside. I also haven't noticed one puff of any smoke out the tailpipe (not only while driving, but standing behind the car as a friend revved the engine)

I guess I won't know until the moment of truth...

 

[thewubs]

Fouling would be the main issue, but if it runs smooth andoesn't blow any steam or smoke, you're probably in the clear anyway.

Here's to hoping it's all good inside. When the weather was Warner a coupe weeks ago (50-60°) there was nothing. With the cooler temps, though, thereis some stream, but nothing that seems out of the ordinary compared to any other cars I've ever owned.

many thanks for your help. :beer: on me k3:

 

[thewubs]

Some condensation in the exhaust is normal, especially in colder temps. You only need to worry if its a lot of steam, and it doesn't stop after a few minutes.

Yeah, I appreciate the clarification. The amount of "smoke" (vapor rather) was of no alarm to me. Again, thanks for your help here. We'll see how it goes in a couple days! k3:

 

[thewubs]

Crazy massive necropost here - it was definitely both the UIM/LIM gaskets and they were both FRIED. I used the revised Dorman UIM (which, according to NAPA, Advance Auto Parts, ect., were the new OEM parts *shrug*) and Felpro gaskets. The kit I ordered off rockauto included the UIM/LIM and respective gaskets, a new PCV valve and parts, and a revised EGR stovepipe. I changed the oil/oil filter, drained and flushed the Dexcool rubbish, and refilled with Prestone green antifreeze mixed with distilled water by me. Alas, no more coolant leakage! :cheers:

However, it is now throwing p0753/p0758/p1860 codes - all relating to transmission solenoids. It also seems to be stuck in one single gear - google says it goes into a "limp mode" and stays in 2nd or 3rd gear until the issue is fixed. It was throwing NONE of these at ANY point prior to me replacing the aforementioned parts, ergo I am inclined to believe it is not actually an issue with the solenoid as the codes would imply. I checked the 20-pin connector that plugs into the transaxle, and it looked reasonably clean, which was a suggestion I found via google as well.

Help! Fixed intake gaskets now trans is throwing codes • GBodyForum.com - 1978-1988 GM G-Body Cars & Community

that is a link to a guy who is having the same exact problem as I am, 100% to a tee.

Any suggestions, guys?