weird coolant leak

[Dilsky]

Ok so this is my major problem as of right now, i have coolant leakinf from the passenger side of my car. The way it goes is, if i fill it up i have driven for over 6 hours and the level stays good. However after i leave it no matter how much i have driven it it leaks down to nealry the bottom of the tank and just stays there. When i drive it at this level it doesn't drop at all no matter how long i drive it or park it for. Any ideas, thanks in advance.

Shawn

 

[KINGPIN33]

Pop the hood and look under your engine to see where its leaking. It's too hard to tell what's wrong from your description. Is your car NA or Turbo? There are many coolant passages that can leak on the passenger side on the engine. Go back to the car and take a very good close look and then report back.

 

[jdub]

Here's the way it works (simple explanation): Assuming a healthy cooling system, it will heat up to operating temp, the thermostat will open and coolant will flow thru the radiator. The coolant will expand as it absorbs heat and vent into the overflow bottle. It will stay this way as long as the coolant is warm. Once the coolant cools off it creates a vacuum, the hose from the top of the radiator works in reverse and sucks coolant back into the radiator. This process happens continously.

If you have a leak and depending where it is, coolant can escape while the system is under pressure. If the leak is in a place (like the rubber seal in the thermo housing) where the coolant can escape, but semi-seals under vacuum it will empty your coolant bottle. In other cases, the leak can suck air into the system and the coolant bottle will be over full, but your radiator coolant level will fall...this will produce a higher than normal reading on the coolant guage as the system loses coolant. A bad heater core can leak, but won't suck air into the engine part of the system...this will allow the coolant to suck back into the radiator from the overflow bottle.

If you have a blown head gasket, coolant can be forced under pressure into your oil or a cylinder...neither of these are good. Check to see if your oil level is rising and/or has a milky look to it. If you are getting white smoke out the back that smells like coolant...that's the indication of coolant in the cylinder. Usually what happens is exhaust gas is forced into the coolant system, displacing the coolant...in this case, the overflow bottle will fill to the top and discharge coolant out on the ground...the car will over heat as well.

The problem with our coolant system is any variation of the above will produce symptoms that mimic something else...a real PITA to figure out. Do the simple things first...get your coolant system pressure tested, check condition of hoses, replace the thermostat & rubber seal, check your heater core. If you want piece of mind concerning a BHG, go to NAPA and buy the block test kit...it tests for exhaust gasses on the coolant system.

Good luck

 

[NDBoost]

Here's the way it works (simple explanation): Assuming a healthy cooling system, it will heat up to operating temp, the thermostat will open and coolant will flow thru the radiator. The coolant will expand as it absorbs heat and vent into the overflow bottle. It will stay this way as long as the coolant is warm. Once the coolant cools off it creates a vacuum, the hose from the top of the radiator works in reverse and sucks coolant back into the radiator. This process happens continously.

If you have a leak and depending where it is, coolant can escape while the system is under pressure. If the leak is in a place (like the rubber seal in the thermo housing) where the coolant can escape, but semi-seals under vacuum it will empty your coolant bottle. In other cases, the leak can suck air into the system and the coolant bottle will be over full, but your radiator coolant level will fall...this will produce a higher than normal reading on the coolant guage as the system loses coolant. A bad heater core can leak, but won't suck air into the engine part of the system...this will allow the coolant to suck back into the radiato from the overflow bottle.

If you have a blown head gasket, coolant can be forced under pressure into your oil or a cylinder...neither of these are good. Check to see if your oil level is rising and/or has a milky look to it. If you are getting white smoke out the back that smells like coolant...that's the indication of coolant in the cylinder. Usually what happens is exhaust gas is forced into the coolant system, displacing the coolant...in this case, the overflow bottle will fill to the top and discharge coolant out on the ground...the car will over heat as well.

The problem with our coolant system is any variation of the above will produce symptoms that mimic something else...a real PITA to figure out. Do the simple things first...get your coolant system pressure tested, check condition of hoses, replace the thermostat & rubber seal, check your heater core. If you want piece of mind concerning a BHG, go to NAPA and buy the block test kit...it tests for exhaust gasses on the coolant system.

Good luck

very good explanation jdub. So far ive had the same issue, when i blew my HG the first time it pushed coolant out through the overflow. No other symptoms besides that. Now ive got the samething, so what i did just to ease my mind is put a new radiator in and retorque the head to 115 ftlbs (from 95 ft lbs) the problem went away (for awhile). It finally came back on Sunday when i was on the freeway. I added coolant on the side of the road and i havent had any issues since. Ive driven the car hard and been in boost alot but never at constant freeway speeds, its weird. Still no overheating or loss of coolant anymore.

 

[jdub]

very good explanation jdub. So far ive had the same issue, when i blew my HG the first time it pushed coolant out through the overflow. No other symptoms besides that. Now ive got the samething, so what i did just to ease my mind is put a new radiator in and retorque the head to 115 ftlbs (from 95 ft lbs) the problem went away (for awhile). It finally came back on Sunday when i was on the freeway. I added coolant on the side of the road and i havent had any issues since. Ive driven the car hard and been in boost alot but never at constant freeway speeds, its weird. Still no overheating or loss of coolant anymore.

Yeah...that's what my motor did. Then I blew the little hose from the top of the head to the hard line around the block. The overheat that resulted killed my stock HG.

Might want to consider a system pressure test...you could have a pin leak and get air into the system over time. Like I said, cooling system problem are a real PITA...can drive ya crazy!

 

[NDBoost]

yup, i almost wish cooleeze would release a upper AND lower hard piping kit for the cooling system

 

[Dilsky]

Sorry about the lack of info. It is an 88 turbo, it runs perfectly fine except for this weird leak. The exhaust is normal, no funky colors or anything like that. it just leaks heavily from just under the front passenger side. However by that time it is fairly wide spread, so i am thinking the leak starts out fairly high.

Shawn

 

[supramacist]

the under belly of my ride is covered in oil so be glad yours is only leaking coolant. I have to find the leak ad tighten shit down or something atleast till I can figure out what is causing all of this bull shiat.

 

[jetjock]

Assuming a healthy cooling system, it will heat up to operating temp, the thermostat will open and coolant will flow thru the radiator. The coolant will expand as it absorbs heat and vent into the overflow bottle. It will stay this way as long as the coolant is warm. Once the coolant cools off it creates a vacuum, the hose from the top of the radiator works in reverse and sucks coolant back into the radiator. This process happens continously.

Jdub, unless I'm reading you wrong I don't believe that's entirely correct in it being a continual process. Assuming a healthy coolant system the rad cap should never relieve during engine operation. The cap only relieves when it's pressure rating is exceeded and that won't happen if the heat load is being removed.

The pressure could increase past the cap's rating after the enigne is shut down however. The cap will then vent coolant into the overflow bottle. As the engine cools and the pressure is reduced the coolant will flow back into the system. Some cars go so far as to try and prevent that from happening. It's one reason many run the fans after shutdown, which my car gas been modifed to do for years. The cap should never relieve a healthy system. Or was that what you were getting at?

Scarebus huh? Be careful with those pedals....

 

[jdub]

Jdub, unless I'm reading you wrong I don't believe that's entirely correct in it being a continual process. Assuming a healthy coolant system the rad cap should never relieve during engine operation. The cap only relieves when it's pressure rating is exceeded and that won't happen if the heat load is being removed.

The pressure could increase past the cap's rating after the enigne is shut down however. The cap will then vent coolant into the overflow bottle. As the engine cools and the pressure is reduced the coolant will flow back into the system. Some cars go so far as to try and prevent that from happening. It's one reason many run the fans after shutdown, which my car gas been modifed to do for years. The cap should never relieve a healthy system. Or was that what you were getting at?

Scarebus huh? Be careful with those pedals....

I should have been more clear...and yes, that is what I was talking about...as the engine goes through daily run cycles and is allowed to cool between runs. It will do this continuously as the engine is run, then allowed to cool down. You are correct, a healthy system will allow for the coolant to expand and it will achieve equilibrium assuming there is no air in the system. You will have a small amount go into the overflow bottle from the greater volume caused by the coolant heating up, but it will get nowhere near overflow on the bottle itself.

On a stock radiator in a hot climate (like PHX), this can occur while the engine is running...basically you are exceeding the ability of the radiator to dissipate the heat due to the thermodynamics involved of having ambiant air approach 110-120. Especially when driving up a grade or running the AC...heat produced by the motor exceeds the rate at which the stock rad can get rid of it when it's hot outside. I have a much larger radiator (CSR) with electric fans rigged to run for a short time after shut down...very effective in keeping the coolant expansion to a minimum. The larger radiator provides the volume (reserve capacity) to deal with hot weather ops.

Yeah...love the side stick. The flt control laws are a lot like the Viper, only the limits are a bit more "restricted"...LOL. Felt right at home when I got trained in it. I was already used to the quirks of fly-by-wire, so it was pretty easy. I have seen some other guys mis-use the rudder though...got pretty "exciting" :eek3:

 

[jetjock]

Got it. I keep forgetting about the WX you have out there. Mine never has to deal with that so I never see the cap break pressure. Runs perfect in all conditions.

I have zero time in Buses but no one I know likes them much. Not that I wouldn't trust the magic (it's everywhere these days) it's just that old joke about how in Hell the French are the engineers . I assuming these days (after NYC a few years back) they've change the software.

It still beats the bizzare deflections that occur in the 737 though. As far as I know they never did quite figure out why the PCUs were doing it. I've read CVR transcripts in those cases and it's enough to creep anyone out.

 

[jdub]

Got it. I keep forgetting about the WX you have out there. Mine never has to deal with that so I never see the cap break pressure. Runs perfect in all conditions.

Keeping this motor running at ops temp can be a challenge out here. I learned my lesson on the cooling system the hard way...I keep the rad cap, thermostat, hoses, etc in top shape. My Supra runs perfect now too, but you can't let the cooling system go even a little bit or you're asking for trouble.

I have zero time in Buses but no one I know likes them much. Not that I wouldn't trust the magic (it's everywhere these days) it's just that old joke about how in Hell the French are the engineers . I assuming these days (after NYC a few years back) they've change the software.

It still beats the bizzare deflections that occur in the 737 though. As far as I know they never did quite figure out why the PCUs were doing it. I've read CVR transcripts in those cases and it's enough to creep anyone out.

LOL...most of the guys who don't like the Bus don't understand it. The best quote I heard was from a 727 guy who was forced to come over to the Bus because the 727's went away...he told me sitting in the cockpit "JDub, now I know what a dog feels like watching TV"

The rudder incident you'r referring to was a AA A300...the pilot used a lot of rudder (rapid full scale deflection) to correct a rolling moment from the wake of a preceding acft. It exceeded the structural limits on the rudder and it snapped off. Computer flight controls are very straight forward from the pilot perspective...yaw is yaw, you don't roll with rudder even at high AOA...you use the ailerons. The computer provides flt control deflection based on how much you move the stick...the more you move it, the more you get. But there is a big difference...at high AOA, the ailerons will deflect more to give you the same rate you want based on a given stick deflection. The computer compensates for you...it's hard for an old school guy to grasp that after 20+ years (sound familiar...LOL)

I got flipped upside down at 1500' AGL in the 320 Bus sim (upset training...the PI saw in my record what I flew in the USAF). I recovered the acft upright w/ a 800' altitide loss...the folks in the back wouldn't have liked it, but it was better than the alternative :naughty: The rudder stayed on the aircraft too...hardly even used it

BTW...I'm pretty sure Boeing installed a control valve to correct the 737 PCU problem.

 

[IJ.]

"The Captain has switched on the inverted flight light so please keep your seatbelts fastened"

 

[jdub]

"The Captain has switched on the inverted flight light so please keep your seatbelts fastened"

You got it IJ...otherwise you'd be the marble in a mason jar :1zhelp:

 

[jetjock]

Lol, I can see how moving from the Jurassic Jet would be a big step. No time in those either. I'm typed in the 73, 75/76, Lear 35, CitationJet, and CRJ.

I know what happened to that A300 but it's exactly the old school in me that expects full deflection below Va isn't going to cause structural problems. I certainly don't expect it to shuck the engines and vertical stab. I'm not against compsites, just that they don't yield the way aluminum does. The ultimate yield point is about all the warning you get and by then it's too late. Ah well, as with all of them something good came out of it.

Man, we're way off topic here. We'd better let it rest

 

[jdub]

Sorry about the lack of info. It is an 88 turbo, it runs perfectly fine except for this weird leak. The exhaust is normal, no funky colors or anything like that. it just leaks heavily from just under the front passenger side. However by that time it is fairly wide spread, so i am thinking the leak starts out fairly high.

Shawn

Sorry for getting so far off topic Shawn. You have two heater hoses on that side...one from the top of the head feeding the heater valve, then from the valve to the firewall. There is also a small 90 deg hose from the back of the head to the hard line that goes around the block...it's hard to see...it on the passenger side, rear corner of the engine. On some motors, there's a rubber plug on a piece of that same hard line just below the hose.

Any of these can leak...if that small 90 deg hose or the rubber plug (if you have it) gives out, all of your coolant will be on the ground very quickly. Not good...mine did that on the highway and the resulting over heat killed my stock HG.

You also want to check the hoses that feed the center section of the CT26 turbo...there's a "Y" shaped tube on top of the turbo going to the water neck and back of the water pump housing.

 

[johnathan1]

I don't mean to threadjack, but....will the NA lower radiator hose work on a turbo?? Mine is leaking VERY slightly, but not causing any overheating... I have heard that the lower rad hose is pretty rugged on our cars, and doesn't usually give out, is this true?

 

[jdub]

I don't mean to threadjack, but....will the NA lower radiator hose work on a turbo?? Mine is leaking VERY slightly, but not causing any overheating... I have heard that the lower rad hose is pretty rugged on our cars, and doesn't usually give out, is this true?

I'm pretty sure they are different...the turbo hose convolutes around before it goes down to the bottom of the radiator. Give Jay Marks Toyota a call...I'm sure Jeff can fix ya up.

 

[Dilsky]

Ok well thanks for all your help guys i am bringing her back on the road this weekend leak or no leak anyways. Finally time for her to come out of winter hibernation. Thanks again.

Shawn