BionicElite

94 vtech del sol with the b16 from factory. 175,000 miles. Car runs perfect with normal driving but as soon as you get on it, (vtech, redline) the radiator reservoir is boiling and spewing. Gauge inside doesn't indicate overheating and stays at a bit lower than half way. When it does boil, the hose coming from the thermostat is completely cold. When no boiling occurs (with babying, shift at 3k and highway 70 mph) the hose is as hot as the other, the way it should be all the time.

Measures I've taken so far:

Changed thermostat

Flushed the system and bled it

Changed fan switch on thermostat housing

Don't believe it would be the water pump so it looks like head gasket. suggestions or tests i could run to insure this is the problem would be appreciated.

ballinboosi

i don't know but that doesn't really sound like a HD, check the oil and see if it has water in it and check your coolant to see how that looks.

nix94delsol

turbojdmhatch

BionicElite

Thanks guys. I have a genuine problem and you're genuine children. Thanks for the advice ballinboosi. Here's an update on the VTEC del sol:

Oil is not milky, is at the second hole on the dipstick

Coolant is clear light green as it should be

Spark plugs have no green tinge to indicate seepage of coolant

No "sweet" smell from exhaust or droplets of water collecting at end of tailpipe

No smell of gas inside cabin with heater on full blast

In short, the few symptoms of a head gasket problem i searched for came up negative. Drove around for 15-20 minutes normal driving, pop the hood and no boiling of the radiator reservoir. Only when its driven hard. Possible blockage in the system somewhere? (but if it was blocked, normal driving would still cause it to overheat...) However, no blockage in the radiator; the coolant mixture poured out easily when it was flushed a week ago.

BionicElite

Nothing yet. However, letting it sit at idle for a few minutes finally gets the thermostat working. But then drive hard and once again the coolant mixture is boiling.

its not the thermostat, not the fan switch, no blockage in radiator, radiator cap is new, and no indication of head gasket issues, doubt its the water pump. So far I'm stumped. Leak down test i'll do next week and we'll go from there. Suggestions?

cherroneballs

Possible faulty thermostat, One of those that where made on a friday at 4:59, or first thing monday morning. just throwing thins out there but thats what it sounds like. did you use the gasket on it?

BionicElite

did the test for the thermostat to make sure it was good. suspended it in a pot of boiling water and it opened up more as the water got hotter. gasket was off, of course, and i put the gasket back on before i put it back in the car. (no tears in gasket, no breaks in spring of thermostat)

Searching around some more and boiling coolant in overflow tank means 1 of 3 things: radiator cap, thermostat, or water pump (or any combination of those). Water pump is the only thing that hasn't been changed out since i got the car not too long ago. I plan on doing that next week. If its not any of those 3, its headgasket or cracked head; none of which the del sol is showing symptoms. The water pump SHOULD do it. Cross your fingers for me. Any more thoughts, throw'em at me. I'll let you guys know if the water pump did the trick.

donvito#1

so ur car not overheatin wat the guage tells u right i would hook up an after market coolin gauge maybe ur stock one is inaccurate and u are overheating

jimmy o.

The water pump impeller could be corroded to a point to where it couldnt keep up cooling at high rpms

yhammer

wow.i,m having the exact same problem in a 1994 civic ex d16 v-tec.I posted on temple of vtec the same issue and was shocked to see this post.I have replaced radiator,hoses,overflow bottle,thermostat and water pump.my car overheats when at higher rpms and boils over into over flow bottle.before I replaced overflow bottle it would leak out of resevior.I now think the people who put in water pump ripped me off with used pump.tried to save money and used crappy labor,they actually left coolent level low originally.everything you posted I have checked already,except water pump being faulty.thank you for posting this problem.if you have any interior ?s.I do interiors for auto.I was going to replace motor.thanks man.

red91efhatch

Man my car started having the same exact problem, took it to honda (dealer) and they told me head gasket, and want to charge $1500 to replace it, the only diffference is I have a bit of water out of the exhaust- I know thats normal due to Cat.... I'm starting to think water pump now that you mention it. hope we figure this out soon

torbs

water comes out of the exhaust because it is the end result of combustion...

EKstacy

Id check the water pump before you go into the headgasket idea. All you gotta do is open the rad. cap with the car running and look and see if the coolant is moving. If you want to you can rev the car and see if it increases with the rpm's and that would indicate a good waterpump. if it is barely flowing, or not at all, then you have a bad water pump.

BionicElite

yeah donvito, theres no doubt about it overheating. gauge works and needle rises like normal as its warming up, but won't rise as i'm hitting it on higher rpm's. A local mechanic was telling me that when driving hard, the sensor for the gauge isn't recieving a signal from the coolant mixture to raise the needle simply because...there is no mixture at that time by the sensor, hence why the needle will stay where its at and not tell me the true condition of the motor.

good point jimmy, hope you're right on this one. Little quote to better explain this

"water pumps DO wear out, especially when you use sh!tty antifreeze which have borates and silicates (which is just a fancy way of saying fine-particled sand) in them. A water pump is actually nothing more than a impeller spinning at high-speed. Antifreeze with borates and silicates will, over time, 'sand' the impeller down to nothing, and the water WILL quit circulating, causing overheating."

Frozen E

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EKstacy &raquo;</TD></TR><TR><TD CLASS="quote">Id check the water pump before you go into the headgasket idea. All you gotta do is open the rad. cap with the car running and look and see if the coolant is moving. If you want to you can rev the car and see if it increases with the rpm's and that would indicate a good waterpump. if it is barely flowing, or not at all, then you have a bad water pump.</TD></TR></TABLE>

You forgot that the car needs to be at operating temp and the stat needs to be open. Otherwise no coolant is going to flow into the radiator and using your method above will give a "false positive"

BionicElite

Well, tried getting to the water pump yesterday. And you know what sucks? 130 ft lbs of torque. Cams keep turning too, for some reason (friend holding brake with 5th gear in). Hopefully my buddy gets the hose for his impact gun today

obuhmyuh

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nix94delsol &raquo;</TD></TR><TR><TD CLASS="quote"> </TD></TR></TABLE>

you jacked my pic! haha i was gonna do it.

yhammer

tested my radiator for exhaust gases and tested positive.head gasket leak is problem.