Waterfall sound behind dash...

[johnathan1]

Okay, here's some background:

I had a BHG when I first bought my car...replaced it with an OEM Toyota HG, milled the head, used Permatex spray, w/ ARP studs torqued to 80ft/lbs. Retorqued @ 500miles.

Present:

Has been fine, except lately, (last month or two) I have been hearing the waterfall sound occasionally...well, most of the time when revving the engine to about 2k, above that, I don't hear it. At first I thought it was my thermo housing (1 stripped bolt, and I used FIPG on gasket)..replaced that, and did everything PERFECTLY w/ all new Toyota gaskets and such. Still had the problem, I found out I had a small coolant leak, fixed that, same problem.

So now, I am at the point, where I am pretty sure it is the HG leaking ehxaust gasses into coolant (right?)...I did a block test, but It came up negative.

What do you guys think? The car did get a little hot a couple of times, the temp. guage never really went above the half-way mark though...Just pushing coolant out...(I believe this was caused by that damn leak) It hasn't overheated recently, or burned any coolant, nothing at all...except for the waterfall sound.

Should I try to save it with a retorque?

Thanks for reading guys, and sorry for the long post.

 

[Nick M]

You have a coolant leak. That doesn't mean it is in the combustion chamber. It can be anywhere.

 

[koulee]

Waterfall behind dash sounds are correlated to the heater core. Either repair it or bypass before you actually start getting a waterfall behind the dash.

 

[3p141592654]

Take your car to a smog shop and have them sniff for combustion products coming out of your radiator. This sure sounds like the beginnings of a BHG. I had the waterfall for 7 years before things went really bad and I had to replace the HG!

 

[jetjock]

Good advice. That's what I do. I put a plastic bag over the open rad and then sniff the bag. Another advantage to owning a gas analyzer. Works great for finding the tiniest of fuel leaks too

 

[suprabee]

You may be already aware, but the heater core is the highest component in the cooling system and air in the system collects there. Do a search here for "burping" the cooling system of air. However, I have tried the methods described and have never been able to remove all the air and I still have the waterfall sound, so I gave up. I drove up a mountain road that was near 45 degree incline (i could barely get out of the car it was so steep), and tried for over an hour with the car idleing, occasionally revving the engine and I still couldn't get all the air out. I don't think I have a BHG. No loss of coolant, no smokey exhaust and car runs fine. Just my thoughts.....Anyone have any suggestions/tricks on removing that air??
rick

 

[koulee]

You may be already aware, but the heater core is the highest component in the cooling system and air in the system collects there. Do a search here for "burping" the cooling system of air. However, I have tried the methods described and have never been able to remove all the air and I still have the waterfall sound, so I gave up. I drove up a mountain road that was near 45 degree incline (i could barely get out of the car it was so steep), and tried for over an hour with the car idleing, occasionally revving the engine and I still couldn't get all the air out. I don't think I have a BHG. No loss of coolant, no smokey exhaust and car runs fine. Just my thoughts.....Anyone have any suggestions/tricks on removing that air??

rick

The heater has to be on full blast at the hottest setting.

 

[suprabee]

The heater has to be on full blast at the hottest setting.

Yes, I know it. the heater was on highest temp, full blast.

Sorry to highjack this thread...my bad..

rick

 

[johnathan1]

Yes, I know it. the heater was on highest temp, full blast.

Sorry to highjack this thread...my bad..

rick

Don't be sorry! You just may help me solve my problem too! lol...two birds w/ one stone!

Also, I believe someone on here posted a link to a device that purges all of the air out of the cooling system...it was like $100-150 IIRC... What is that thingy called?

 

[suprabee]

I believe someone on here posted a link to a device that purges all of the air out of the cooling system...it was like $100-150 IIRC... What is that thingy called?

yes...here are the two I found using the search. I don't want to spend the money for these, since other than the waterfall sound, I have no engine problems and like I said I don't think the head gasket is leaking. If it is leaking even just slightly, there would be a slow loss of coolant over time. This has not happened in the 7 months I've owned my MKIII. My opinion is that raising the front of the car, allowing air to bubble out, removes some but not all of the air. Air in the heater core has to make it's way through many hoses and passages before it escapes from the top of the rad and I think it is not a 100% sure method...IMHO...but I'm open to suggestions....



http://www.etoolcart.com/browseproducts/Air---Evac-System-MIT4700.HTML
and this one too....
http://www.radcapproducts.com/airevac.html

Rick

 

[3p141592654]

You could try loosening the hose that goes to the heater control valve and see if you can get any air out there. That is pretty much the highest point in the cooling system.

 

[Nick M]

I have no engine problems and like I said I don't think the head gasket is leaking.

Actually, a coolant leak is an engine problem. BHG is a symptom of another problem, such as a leak. Not saying yours is gone now, but find it and fix it.

Air is a great insulator, and coolant is a terrible one. So it leaves hot spots in the head.

 

[johnathan1]

You could try loosening the hose that goes to the heater control valve and see if you can get any air out there. That is pretty much the highest point in the cooling system.

I would try that, but won't coolant spew everywhere?

 

[Boss302]

water fall sound...is it from behind the glove box? where is it coming from?

 

[3p141592654]

Don't try this with a hot engine! Yes, it will make a mess, but you just want to loosen it a little and see if you can get any air to come out. Don't pull the thing off!

I would try that, but won't coolant spew everywhere?

 

[johnathan1]

water fall sound...is it from behind the glove box? where is it coming from?

At first I thought It was coming from behind the glovebox, but it sounds like it is coming from right behind the two middle A/C vents.

 

[Boss302]

heater core sounds like cause thats the Only thing that would contain a fluid around that area.

 

[johnathan1]

If it were exhaust gases from a leaky hg, wouldn't there be coolant overflowing out of the overflow bottle, because of the pressure from the cylinders?...yea, I think i said that right....

Anyone?

 

[suprabee]

Actually, a coolant leak is an engine problem. BHG is a symptom of another problem, such as a leak. Not saying yours is gone now, but find it and fix it.

Air is a great insulator, and coolant is a terrible one. So it leaves hot spots in the head.

Nick, sorry but I don't understand your post. Did you read all of my previous posts in this thead? Yes, of course a coolant leak is an engine problem...and a BHG can be a symptom of another problem.

Ok, to clarify once again......

1)NO visible coolant leaks on the outside of the engine and NO coolant dripping on the ground underneath the engine.
2)I have NO...ZERO...NILL.. coolant loss in the past several months of daily driving, meaning that when I remove the rad cap, the coolant is topped of and there is always coolant at the "high" fill line in the overflow tank.
3) I have removed the spark plugs and there is only normal combustion deposits on them.

Rick

 

[suprabee]

You could try loosening the hose that goes to the heater control valve and see if you can get any air out there. That is pretty much the highest point in the cooling system.

That is a good idea. In fact, I tried something similiar (after trying the standard "burping" method several times) ...here is what I did to BOTH the inlet and outlet of the heater core. I bought about 3 ft. of clear tubing the same diameter as the coolant hoses, so I could see any air. I started with the outlet side (just above the EGR valve). Removed the clamp and hose and attached my clear 3 ft hose and clamped it on. To the other end of the clear hose, I attached a large 2 quart funnel and hung it from the front of the raised hood. I began pouring distilled water into the funnel. At this point, the funnel was at least two feet above the entire engine. The hose and funnel filled up with water; however, I could not get any air to bubble up. The water in the funnel was definetly higher than the heater core, but still to no avail, NO air bubbled up. I reattached the coolant hose and moved to the inlet side and repeated the process, but no luck.

I was frustrated at this point, so I said f&*^k it! and grabbed my garden hose and attached it to the inlet side and removed the hose from the outlet side, turned on the faucet full blast. I flushed all the red coolant out of the heater core and stopped, reattached everything, started the engine.....AND......

WHOOOSH!!!! still air in the heater core!!!! So I gave up. I believe that the heater core is shaped so that the inlet and outlet pipings are not the highest part of the heater core itself and that the center of the core rises above the pipes and this is where the air is trapped. So, all my flushing and burping simply moved fluid inside the core, but didn't remove the air. I'm sure that the vaccum equipment I posted here earlier would be the only thing that could ultimetly remove all the air.

Rick