Hello all,
I have a 2005 Chev Venture van with 120k on the odometer, I have owned this vehicle since new so I know it was taken care of. This van has been using a very little coolant the last two years but now it seems to be using more than normal, A wild guess would be a quart every 700 miles. I am also well aware of the LIM gasket issue with these engines but I thought that this was fixed by the 2005 model. There is no visible leakage on the engine or radiator(repaced about a year ago) or by the heater core. There is no coolant in the oil( as far as I can tell) so I am assuming its getting sucked into the intake side of the engine (does this sound reasonable)??

Any advice on what to check in more detail to help me rule out anything but the LIM gasket would be greatly appreciated.

Thanks in advance for any help given!!!

I take it that since you have always owned this vehicle, it has never had a lower intake job done......Where they tend to leak externally, is in the Valley of the Kings, or rather the valley where the lower intake meets the heads and the block in between them.....

Look under the throttle body with a light, looking for pools of coolant trapped in indentations in the top of the block, or a stain trail....look on the opposite side, behind/below the PS Pump, in the "valley".....It would help to pressure test a warm engine overnight, and look for leaks, everywhere......if nothing found, then adding a coolant dye, and using a blacklight may be necessary.....check everywhere.....hoses, water pump, radiator, hoses, overflow tube, etc.

What you have, when you lose coolant, is the creation of a possible air bubble.....this can cause the engine to overheat, and on these vans, it'* ripe for causing headgasket problems on cylinder #1......

So have the lower intake checked out and repaired if necessary.....otherwise, a head gasket job is more expensive than a lower intake job....

Do you smell coolant from the exhaust, engine comprtment, or the passenger compartment?

Tech II, thank you for your quick and detailed response!! Here are a few quick responses to your questions.
Ans1 There has never been a lower intake job done on this vehicle.
Ans2 I have checked all the area that you have mentioned and don't see any signs of coolant leakage.
Ans3 I do not smell any coolant in or around the vehicle.

Having said that I still do not want to rule out the possibility of an external leak, so I plan on getting some dye in the system and run the vehicle for awhile and check it over again. Its the middle of winter here in Wisconsin and I don't have access to a heated garage so I do not want to attempt this job (LIM) unless absolutely necessary!!

I will post back again with my results and ask for next steps in the near future.

Thank you again "Tech II" for your help in this. I know this particular issue has been beat to death on this forum so I was concerned no one would be willing to reply to this topic, so your help is greatly appreciated. You will hear back from me soon. John

Well, keep an eye on the level, top off if necessary....I would open the radiator cap and top off the coolant in the radiator first, then top off the reservoir to the cold mark....you might find some orange/brown gunk on the radiator cap....that happens when dexcool is exposed to air....do this on a cold engine....and keep a record of coolant loss per mile, so if it dramatically increases, you know to repair it....but with coolant loss comes air pockets, so be aware of loss of heat due to one, and possibly overheating the vehicle....if you know how to properly burp the system, that would be good....

Not smelling coolant in the passenger compartment is good, kind of eliminates the heater core....

Dye is your friend, especially, when it is a small leak.....

OK thanks again. I will get some dye in the system this week.
I will also research on how to properly burn the system and also keep a close eye on coolant usage.
I will let you know of any new findings.

John, I had the same symptoms you describe last summer on my 2002 Bonneville. I kept checking for external leaks and hoping it wasn't the LIM gasket. Unfortunately it was. I can sympathize with your weather issues. It was only 10 degrees for the high here in Connecticut yesterday. Wind chills were -20+. now they are calling for snow tonight and temps in the 50'* tomorrow with heavy rain.

Two areas to check that I didn't see mentioned are the coolant bypass elbows and the spark plugs. When my LIM gasket went, coolant was getting into one of the cylinders and the plug was wet.

If you don't find an external leak and the van is running ok you can try to push it till your weather gets warmer. But that coolant has to be going somewhere.

In my case I didn't think it was in the oil because I didn't see anything on the dipstick. where I found it was on the oil fill cap. I didn't see it at first because it was in the recess of the cap.

if you do decide to push the repair off till spring you may want to consider changing the oil a couple of times. If coolant is getting into the oil it can do a lot of damage. I had a post last year about coolant in my oil. the people who replied gave me good advice.

hope this helps. good luck.

AAScreen,
Thanks for your input and suggestions. Whats going on over there with your weather?? -20 Degrees one day and 50 degrees the next: global warming or what!!!!

I appreciate your advice as far as putting this off for a bit because I was concerned about doing damage to the engine running it like this but as far as I can tell I have no coolant in the oil, so I was not quite as nervous to put this repair off until I or a real a professional can do it.

Before I left for work tonight I added an ounce of dye to the coolant system. My wife had a bunch of errands to run with the van this evening so when I get home tomorrow I will take a look and see if I spot any external leaks.

Thanks again for your assistance. John

Check the oil dipstick levels every now and then, if you notice the oil level going up then you know the coolant is getting in there.
If you do find it is the LIM, and want some help/tips on doing the job, and on choosing the parts just let me know, and I'll be happy to help!

WilliamE
Thank you very much for your advice and generous offer of assistance ( I am very impressed with the level of support folks are willing to give on this site) and I think I may be needing some of that help in the near future as I try to rule out any thing else other than the LIM.

I am on day two and 30 miles on the vehicle since adding "dye" and have not been able to spot any leaks.

Does it make since to pull the plugs looking for any traces of dye on them or in the cylinders??

I am very confident that there is not any coolant in the oil but will continue to watch it very closely.

Very welcome John, I felt the same way about the site when I first came here for help, which is why I have been here trying to pay it forward ever since.

If you have not found any external leaks yet then chances are it is internal.
Have you ever put anything down like some cardboard, and parked the car over top of it after driving it for a bit?
That would not help you find the location of the leak, but it would help verify if there is an external leak.

If coolant was getting into the cylinders I think you'd be having some issues with the way it runs, even if it was just a tiny bit.
If it was a significant amount the motor would most likely already be hydro-locked.

When you check the oil look for bubbles inside the upper rim of the oil cap, and also on the dipstick.

Have you done a pressure test on the coolant system?
You may be able to rent the tool from a local autoparts store, is not Amazon has them for a fairly decent price.
http://www.amazon.com/Mityvac-MV4560...5667430&sr=1-3