Hey guys. This may have already been discussed elsewhere, but this is all weird to me so I thought i'd post it.

Sometimes for a week or two out of a month every month or so, when I am accelerating beyond 2000 rpms from a complete stop, I hear a "gurgling" or an "air in system" noise coming from the passenger side dashboard (Heater core maybe?? Could this indicate a problem with it?)

It has been happening since I had the intake manifold gasket replaced in late February 2009 (Bought FEL-PRO intake gasket set at Autozone). I am sure the repair shop put DEXCOOL in because the coolant is orange in the "overflow tank" (not sure what the "technical" name is). I was reading about how DEXCOOL eats away gaskets here on the forum last night (and also figured out why my intake gasket started to leak!!!) and the other trouble with it, so I am looking to get the coolant flushed tomorrow with the "green stuff" since I am going away to college in 18 days, ...... hours, ..... minutes, ..... seconds (as per countdown clock on my new homebuilt computer!) so I don't have coolant-related problems on the road to college (I've never had to break out the AAA card for anything (knock on wood). Any issues I have had so far were not serious enough to completely disable the truck or require a tow truck. I'd like to keep it that way, until of course it reaches 200,000 miles or more and something else goes wrong!).

Would flushing the system solve the intermittent sound? I haven't had any overheat situations (the temp always stays either on the 210F (100C) mark or one or two notches below even in 90F weather) since the incident on the ride home from the dealership (55 miles away) in November 2007 when we bought the truck (of all times!!), when we discovered a 4" gash in the radiator. The truck was emitting white steam and a loud hiss from under the hood, the heat stopped working, the temp gauge was almost maxed out and the "CHECK GAGES" light was on a couple times. We stopped, refilled the cooling system with plain water and finally made it home. Radiator was replaced the next day and the hoses were replaced 2 months later. We had no problems involving the cooling system after that except for the leaky intake gasket (slight coolant leak from just to the left of the A/C compressor. No gushing or anything like that. No oil contamination as far as we can tell (oil change place didn't mention any milk-colored oil when asked (is that the right color when contaminated by coolant?) and the dipstick oil wasn't any funny color) Just a little drop of coolant appearing when the engine is running, and it sealed as it warmed up.).

(Maybe I go into too much detail on my posts and bore you guys? Maybe I just like to type....)


Thanks for any advice on this matter.

ComputernerdBD

 

BS! DexCool does not 'eat' gaskets. The problem is the gasket itself that GM used (and later changed). Replacing it with the FelPro solves that problem.
You may have air in the system. Air and DexCool are not good partners. Elevate the front with the right side slightly higher. Remove the radiator cap and run the engine up to temperature, let it cool and repeat. If any air has burped out, add coolant to bring it up to the correct level.
If there is no air trapped in the system, then you have a plugged heater core. Try flushing the core, but if that does not work, it will need replacing.

 

To make a long story short, Completely get the dexcool out of the system and put reg green prestone antifreeze in,, second that noise is air in the system... That has been mentioned here on the board numerous times.. If i can find the link i`ll post it up..

 

Not to turn this into a green vs red/orange/whatever thread, but as stated, it is pure FUD (fear, uncertainty, and doubt) that dexcool eats gaskets. There is a particularly long thread in the 2nd Gen Tech area on this very topic that I encourage anyone to read in its entirety if they really want to understand what is going on.

The last thing I will say in regard to green-vs-dexcool in this thread is this; I have seen green coolant cause the exact same IMG failures as dexcool equiped vehicles. The reason for the failure is material choice for the carrier (the rigid plastic frame which has an o-ring style overmold to provide the seal). Most often the swelling is exacerbated by over torquing and/or uneven torquing of the LIM bolts. To repair this properly, get the updated metal framed gaskets available from Felpro, PN MS98002T, and follow the tightening sequence to a 'T'. The carrier will not swell on these, but proper torque is still very important to getting a good, lasting seal.

And that noise is definitely air in the system which is bad regardless of the coolant used.

 

UPDATE: Took truck to Valvoline Instant Oil change. They refused to put anything in unless it was DEXCOOL. I said "Fine whatever. Do it" The mechanic advised me he has a friend who is a GM mechanic and that GM is not ready to admit the intake gaskets are a design fault and if I already changed the gaskets, putting DEXCOOL in wont harm them. He said the problem was the old intake gaskets that chemically reacted with the DEXCOOL that caused problems. I said I had FELPROs put in (MS95817 from Autozone). He said that it shouldn't harm it. Oh and by the way: This Valvoline franchise doesn't seem to be competent in the least. The mechanic who brought it into the bay tried to start it when it was still running. I was walking into the building and I heard a loud, weird noise like a failed start or an engine stall (NEVER happens with this truck. NEVER) (my heart sank because I knew it was the starter). I walked back to my truck and asked "What's wrong?", the guy said "oh..... you left the e-brake on". Yes, it was on, but that was definately the starter, not a rev with the parking brake on. Bottom line: I am going to start to learn how to do this stuff by myself or take it to our friend who is a mechanic (40 min away) because I can never find any chain places locally that can do stuff without messing up something.

OH and get this: There is STILL air in the system. Same noise. It came back after they did the flush. Everything still works fine, including the heat (hot when I have it above 82 and it was working well over the winter when I had it cranked up above 80F) and A/C and it isn't overheating or anything.

 

If the sound persists, there is likely more air in the system. It could be signs that the heater core has become restricted.

 

What is so weird is that there was no noise until the intake gasket was replaced. Would I need a new heater core or is there a way to get rid of the air?
Also I noticed on the receipt from Valvoline that they put in 7 qts. Is that right for these trucks?

Also did I get the right gasket set for this truck? It wasn't the same part number..... If not, did I still solve the problem for good by getting the one I got?

 

Did you read my post (the first reply to your original)?

 

Opps. Sorry. Probably going to try that tomorrow if I have time. Thanks for the advice.

 

I don't know how to say this, but I think it fixed itself. Yesterday, I took it up to 3500 rpm on a sudden acceleration pulling onto a dangerous highway. I turned off the a/c and radio and I didn't hear anything. After I got home, I revved it to 2500 (past the point where I normally hear it) and didn't hear a sound. Before that ride, I didn't drive it for 48 hours. Weird....... I would seem that the "Enterprise-D" is never short on surprises (lol)