question, I am losing coolant slowly,no puddle underneath, I had the radiator serviced less than a year ago including... new top neck,bottom neck,top and bottom hoses,thermostat,cleaned,rodded,new cap. I am losing coolant like I did back when I replaced the coolant elbows next to the belt tensioner a couple of years ago? mysterious loss with no obvious wetness anywhere?? I checked the elbows as I replaced with the plastic ones, not knowing there were aluminum ones at the time! I cannot find a leak or wetness anywhere when car is hot!! does anybody have any other idea for me to check?? thanks in advance! this site is so very helpful on working on these 3800 engines! I miss my 327 c.I. '68 Camaro, so simple,so much room!! lol!

 

1. You could be burning coolant if the lower intake manifold gasket is leaking. Check for sludge under the radiator cap and around the radiator neck.

2. It could be a leaking transmission cooler allowing it to leak into the trans. fluid. Check for discoloration of the trans. fluid (yellowish color), and/or condensation and a slightly high reading on the trans. fluid dip stick.

 

Are you smelling coolant while driving or when walking past the front of the car when you shut it off? My daughters Malibu had the coolant smell and it ended up being the clamps for the heater hoses needed replaced. We never saw fluids puddle as it apparently burned off when it hit the exhaust pipe / block. Who knows?

 

plumbob, Thanks first of all! , I do have some sludge on cap and in the rad neck? how can I diagnose this problem for sure?? thanks!!

 

Intake gaskets are the usual culprit, very common as these cars get some age on them.

 

Water pump?

 

Claydoh.
As Aerocope86 mentioned, the LIM gasket leak is a very common problem with our cars. If that gasket is original it's probably is the culprit. Depending on how bad the leak is, you may see white smoke out the tailpipe. You'll know for sure if you see what looks like a chocolate milkshake in the "Galley" with the LIM removed. Replace the OEM nylon gasket with a aluminum reinforced Felpro one. I also recommend replacing the Upper intake manifold with an improved Dorman one while it's off, and you might consider new or remanufactured fuel injectors while you're at it. Here's a great thread about the problem:

https://montecarloforum.com/forum/en...acement-41617/

You can get parts much cheaper on eBay than the thread says.

Hope this helps, keep us posted.

 

You can do a cooling system pressure test.

Auto zone or Advance have them to loan.

Easy test to do.

Does your heat blow nice hot heat as if it was a head gasket you would be getting air into the cooling system and on some cars (my 04 Impala) will air lock the heater core.

If is your intake then unless cooling system gets really low you should still have heat

Others have mentioned milkshake look to your oil, under oil fill cap

 

Did a little research and found this thread from another Forum about Dexcool sludge, how to clean it out, and LIM gasket leaks:

DexCool Sludge; Cleaning | Cooling System Fluids & Additives | Bob Is The Oil Guy

 

Thank you all for the input, much appreciated indeed! been doing some research on interweb and you tube,looks like quite the involved job for a shadetree like me?, but do-able nonetheless! rock auto has fel-pro aluminum lower gaskets sets for $51 and Dorman upper complete kits with actual new upper manifold, gaskets, egr tube, injecter o rings, throttle body gasket etc, etc, for only $64 also! I fig If Im gonna tear the motor down that much I might as well replace it all including valve cover gaskets while Im down there! Also, Question: did anyone else get a recall in mail about a recall on a earlier recall about engine fires? I had this done at dealer years ago for spark plug channels leaking oil could cause a fire, now this new one says they will replace the valve cover gasket and remove the plastic oil fill tube? info yo follow when they have the replacement parts??