Newbie taking on '03 Montana 3.4L, advice needed

[Big Tom]

Well, bought the van dirt cheap cause of course there is engine problems. Apparently this van has 200K on it but the engine has already been replaced at some point with one with only 70K, insider knowledge of the place the previous owner took the van to for the engine swap I know it's a shady shop so I have some doubts the motor they put in had only 70K

Anyway... story goes guy was driving down the highway, noticed it was overheating shut it off asap since last time they overheated the engine it needed to be replaced. He had it towed home, and it sat for 6+ months before I bought it. We tried to start it, turns over but only kindof coughs a little, and noticed the rad was low maybe empty couldn't see all the way down so we put some water into it and it started pouring somewhere out the back of the motor.

So, I'm guessing LIM gasket, but the fact the van isn't starting has me wondering about the condition of the head gaskets, would explain the poor startup/coughing. So, I'm thinking tear the motor out and see what's going on. Anyone got a detailed explanation how to do this in a Montana? The subframe needs to be dropped out from under the van correct?

And if I decide since the engine is out to do some replacing, is there a list I should do? Timing chain/belt? Thermostat? Are injectors an issue with these motors?

And gasket sets, of course I'm going Fel-Pro but I was curious between these 2 kits

HST9071PT1

http://www.rockauto.com/catalog/moreinfo.php?pk=1292288

HS9071PT1

http://www.rockauto.com/catalog/moreinfo.php?pk=393578

Do I really need the premium armored metal one or will the other one work just fine? I mean it's a minivan, and the system will be flushed of all Dexcool and replaced so I'm not sure if it's worth it to get the best... plus I can get a smoking deal on the cheaper set


Then I guess I need new bolts for the LIM... do I need new bolts also for the head? Whats the torque specs for those???



Any information would be appreciated, hoping you guys can help me get through this overhaul.



Side note... I also have a 3.4L engine with 155K in a '02 Impala... I know it runs but was planning to sell it if I could get the other motor in the Montana going... or do you think I should consider swapping them out doing the gasket upgrades on the Impala's motor and sticking it in the Montana?

[Rootie524]

chances are the car at one point had dexcool coolant in the engine which will eat through your gaskets. so its possible it is indeed your LIM gasket or head gasket. and i hope for your sake the coolant didnt mix with the oil and cause a bubbly, thick, disgusting concoction.

and worst case scenario you have a cracked block or head. can you try to find out where the water pours out from. someone may be able to help you out more from what you said but i like to take it one step at a time. you have a problem, find the source. im in the process of fixing a major misfire and with the help of everyone here and alot of time spent i narrowed it down to a fuel issue. trouble shooting sucks... lol

u do need new LIM bolts if you remove it and you definitely need new head bolts. i forget exactly the torque specs but it was something like 90ft/lb + a quarter rotation. im sure that is completely wrong but its just an example. you should get a haynes..nifty little books.

welcome to the site by the way!

[Big Tom]

Anyway I look at it I'm going to need to do the LIM gaskets, be it the engine in the van or if I end up using the one from the Impala. I'm just wondering if I shouldn't just order the big kit and do the heads at the same time?

I know there is a chance for a crack in the block or something major since the water is pouring out the back somewhere, but I can't see much of anything cause it's so tight in the engine compartment, I have a lift in the shop I'll be doing the work in but havn't had a chance to lift the van up to find out for sure what's going on.

But, all the situations I can think of, that engine needs to come out... I think I read somewhere with ALOT of cursing you can replace the LIM with the engine in the van but I'm not sure if that's true??

But again, likely that engine needs to come out. I'm looking mostly for info/direction how exactly to do it and any tips/tricks since I've never dropped a subframe before.

And I like Haynes manuals, but I also don't like them... had some experiences buying them for vehicles I own only to find out for some reason even though they say they covered my year it excluded entirely my model of carbs etc which is why I bought the book in the first place... So since then I like to talk with actual people who have done what I'm planning to do.

[Rootie524]

Well I'm not a van guy so i dont know how much (or little) room you're talking about. but i know in a nbody malibu you can easily replace all the way down to headgaskets with the engine still in the car. i would imagine the van should be similar.

and yeah..even if it's just a LIM gasket issue, you need to take it off. and at that point why not remove the heads and nip that in the bud. chances are you'll have a blown head gasket soon enough anyway. so if i were you i'd do a complete top end rebuild.

all new gaskets, clean some parts (purple power works wonders) and put it all back together paying close attention to the condition of the heads. and make sure you have a good surface on the block and the heads (have them milled if its really rough) so it creates a good seal.

and to see if your really screwed id pull the oil drain plug and see if its oil or oil and coolant. other than that, best of luck. im sure i told you a lot you already knew but it never hurts to mention things again.

[Big Tom]

Well I'm not a van guy so i dont know how much (or little) room you're talking about. but i know in a nbody malibu you can easily replace all the way down to headgaskets with the engine still in the car. i would imagine the van should be similar.

Biggest thing is it's no where near open as the car and also the back half of the engine is covered up, I'm not 100% sure if I need to drop the motor maybe it can stay in and have all the work done but I haven't found anyone who's done it to say yay or nay

[boscov6]

You have room even in the van,the rear head would be a biatch but the UIM/LIM would be no prob, once you release the upper dog bone motor mounts the engine assembly can be rolled forward for more room.PM Sent

[bszopi]

Re: Newbie taking on '03 Montana 3.4L

I think I have a write-up for doing at least the LIM gaskets on a van. It was sent to me by a fellow member, but I just haven't gotten it up on the site yet. I will try to get it up ASAP.

To make a correction from up above, you do not need to replace the manifold bolts, only the head bolts.

Sent from my Devour using Tapatalk

[Tbay99Venture]

But, all the situations I can think of, that engine needs to come out... I think I read somewhere with ALOT of cursing you can replace the LIM with the engine in the van but I'm not sure if that's true??

Heads are totally do-able without removing the engine. Just dealt with both heads on a '99 Venture last March. I wanted to remove the rear manifold before taking off the head which was a lot of trouble, but it was possible.

I'm betting your leak is a freeze plug. That will be a fair amount of trouble to replace with the transmission in the way.

But again, likely that engine needs to come out. I'm looking mostly for info/direction how exactly to do it and any tips/tricks since I've never dropped a subframe before.

IIRC, A thread somewhere on this forum shows a stripped subframe. The remark is that they're surprisingly heavy.

And I like Haynes manuals, but I also don't like them...

The one I've been using is fine for the most part. But I think some of the torque values (mount bracket to transaxle bolts, subframe bolts) were inflated compared to other things I've checked.

[Rootie524]

that's my bad then. i was always told to replace LIM bolts. they came with the gasket kits i got anyway.

[Big Tom]

Heads are totally do-able without removing the engine. Just dealt with both heads on a '99 Venture last March. I wanted to remove the rear manifold before taking off the head which was a lot of trouble, but it was possible.

I'm betting your leak is a freeze plug. That will be a fair amount of trouble to replace with the transmission in the way.

The idea of the leak simply being a frost plug has crossed my mind a few times, would be nice if that's all it is that's wrong with the van but I have my doubts since it's not starting up. I'll have to do some more digging and find out exactly what's leaking, cause right now I'm just guessing what it likely is. I emailed the previous owners again asking for more information on the engine swap they had done and if on the bill the charged for new gasket sets... being such a common issued you'd think while the engine is out sitting on the floor why not do the gaskets before install. OR... perhaps they did swap the gaskets and didn't properly torque the bolts or maybe even reused the head bolts who knows.

That's the worst part about this whole thing is I hate shady shops... even though it sounds like it is possible to do the work with the engine in the van I almost want to pull it out just to look it over good and try to figure out what they did and if they skipped any corners.

Back to the gasket sets though, if I'm planning on chemically flushing/removing the old DexCool from the system do I really need to updated metal gasket sets or just the basic Fel-Pro will work fine?

[walterdude]

From everything I've read around here the only way to fix the famous LIM problem is with the metal gaskets. A few GM Techs swear by the redesigned GM gaskets, but most go for the metal... When I do the gaskets on my 3100 I plan on going to metal.. I figure why take chances for a few dollars....
Good luck,,,
Tom...
It might be just as easy to drop the engine/subframe,,, tho I haven't worked on a van... It really wasn't too bad on my 93 Z34,, did everything by myself... And I'm missing a leg on top of it!!
Here's a link to some pictures I took of the job. Check out the engine/tranny jack I made from an ATV jack. Made the job EASY and SAFE!!!

http://60degreev6.com/forum/showthread.php/38381-Engine-tranny-Swap?highlight=

Later: I see you have a lift, forget about the ATV jack!!! The more I think about it, it probably would be a good idea to pull the engine, easpecially if you've got a lift. You don't say where you live but, if it got cold enough to blow out a freeze-plug you could have a cracked block. Considering the extra/more difficult work a in car job would take and the chance of damage from freezing (possibly), it wouldn't really be much more work to drop the engine and it WOULD be much easier to work on. And you'd know for sure the block is OK before doing all the work... As far as swapping engines: not knowing where you live it might be illegal to put an older engine into a newer car...

[Big Tom]

I live in Saskatchewan Canada and the guy did say it was Nov or whatever when this problem started so not the dead of winter but still likely cold out. We have weeks of -50C where you get warnings on the radio any exposed skin will freeze within 2 minutes sortof cold... so yeah fairly extreme

If it doesn't look like to much more work to pull the motor I just might do it and while it's out do a complete check over. I got a copy of the reciept from the previous owners and it says $1401 for a used engine... pricey so if they're telling the truth likely it would be a low mileage one. Also shows replaced upper/lower rad hoses and I think even the rad, and all new plugs... cool. Saves me a bit of cash since I was debating doing all those things also!

[Big Tom]

So got the van up on the hoist today and am currently working on pulling the subframe, going well except for I can't seem to figure out how to disconnect the connector on the brake booster? Big bugger of a plug and it doesn't seem to want to move...

Anyway while I was at it I started draining the coolant which looks a green/yellow what little is left in the rad so that's good they didn't refill with Dexcool at least. But pulled the oil plug and some coolant came out, so pretty much for sure the head gasket is gone.

So what's a guy to do? How bad is it that there was some coolant in the oil? It didn't seem like a pile of it but when I first opened the drain it came out plus for the first few seconds of steady/thick stream it was oil/coolant then cleared up to just oil.

I know it's not a good thing and can take out bearings etc, but what's a guy to do? I do have that engine in the Impala sitting not to far away, would take some work to swap over and it apparently has 155K opposed to only 70K this Montana engine is "supposed" to have.

[Tbay99Venture]

I'm surprised nobody chimed in. You had the mindset to pull the engine anyway so why not proceed with the plan? Then with it down it's easy enough to see if the coolant can be explained by the gasket or if there's damage to the block. And it wouldn't be that hard to pull the cam and give the bearings a real good inspection. Depending on what you want to do with the van, if the cam gives you worries why not mix and match the best parts onto the Impala engine? The internals ought to have lots of life left and you would have plenty of low-mileage accessories to put on it.