coolant problem

i have a 94 3.4L and i have a problem where i will always be missing about half a gallon or a quarter gallon of water in the radiator every time i drive it

so far i replaces the radiator, radiator cap,thermostat,thermostat sensor, fan........ lol im stuck i don know what can be the problem a few months ago i had changed one of the head gaskets that had blown do to a water leak in the radiator but the car drives fine so i dont think it can be it is there any where else that i should be looking?? and i look under the car and no water drops... i really dont know what to think about it lol so if you guys can give me your advice i would really appreciate it thank you:bow:

also i always mix 50% water and 50% coolant fluid

That is alot of coolant to be losing so it should be noticable somewhere. Did you give a thorough examination of the motor to make sure there isn't any noticable traces of fresh coolant anywhere. Are your radiator hose connections tight? How is the oil level, higher then normal, milky appearance? Also, it might be worth checking the line that runs from the radiator to the overflow tank and make sure that doesn't have any cracks in it.

I had the exact same problem, turned out to be a partial clog in the overflow hose. It was the Dexcool crap that dried up and solidified. It would allow the coolant to blow past it when under pressure, but wouldn't draw back under vacuum when it cooled down, it would just colapse the tubing.

I had kept adding coolant, adding coolant, didn't even realize the overflow was overflowing.

I also had that same problem many years ago. It turned out to be the water pump. It has a weep hole just underneath the pulley... you may need a mirror to see it. This weep hole allows a little coolant to leak out when the bearing is starting to go due to wear. Its supposed to be an indicator to let you know to change the water pump rather than it just seizing on you in the middle of nowhere. It usually just has a small stream dripping only when the engine is running and hot. It is very easy to miss but can definatly leak that much coolant at a time. Something to check anyways

thanks guys im going to go check it out today

well i finally figure out where its leaking i started the motor and waited about 15 min just starring under the hood finally when i shut it off after about 3 minutes it started to leak out from the hose the goes to the thermostat and it would leak onto the block and the block would evaporate it since it was hot so thats why i couldnt figure it out

now i just have one more problem to fix and the car would be great it feels like it has no pull when you hit the gas im going to try to bring it to a mechanic to check it out., when ever i would go and hit the gas it would pick up very slow so i checked my spark plugs and everything is fine i changed all the filters and oil and still the same thing. and the engine runs fine so thats why its kind of trowing me off

Are you getting an SES light? Maybe it is a clogged cat, but hard to say. As for the leaky hose, have you tried tightening the clamp?

i only see a ses light when ever i drive passed 60 mph and then slow down i dont know why ? i even changed the egr valve but still the same other then that i brought the car to 4 different mechanics and they all said that the mechanic didnt do a good job putting the head gasket on and thats the problem. because when ever i would drive it and i would rev it up to about 4,000 rpm it would over fill the reserve and spray out so my dad still says he thinks that it might be the water pump but after having everyone tell me it the head gasket im starting to lead towards it i donno

so far i put back the thermostat and it over fills more then ever

i went to a friend that works at a discount auto parts and he told me that i can get the 3.4L engine brand new for $1,500 and it comes with a warranty. so im starting to think if it is the head gasket i might as well just drop a new engine in it would almost be for the same money? but anyways is it passable it can just be the water pump?

You might want to try to get it scanned to try and get the history codes for the SES light. When the reserve tank is overfilling, is the car overheating as well?

no the car doesnt over heat only when the reserve over fills to much it will over heat from the lack of coolant and i had them scan the car and they told me that they cant figure it out because the ses light has to stay on for them to get the code?? im not really sure if that is true though

My only other guess at this point would maybe be some air trapped in the system, which could be relieved via the bleeder screws. I would have to assume that if you had a bad head gasket or if it was poorly installed, you would be getting the crankcase oil mixed with the glycol and it would be pretty noticable. Also, when you replaced the radiator cap, did you verify it was the correct one?

well when i changed the cap my original cap said 18lbs so i put a new one that also said 18 lbs. by the way about the trapped air that might be a possibility because every time i opened the tub that connects to the thermostat i never spilled any water because there was plenty of air over there. i mean the fluid level wasnt high enough to spill everywhere. where is the bleeder screws on the 3.4L ??? maybe that can be it? also how can i check or tell if there is a little bit of oil in the glycol fluid?

I'm not sure where specifically they are. The thermostat housing is usually a place to start looking.

There isnt a bleeder screw on the 3.4, at least not one meant for it. The easiest way I've found to bleed the 3.4 is to take the Temperature sensor out of the Drivers side cylinder head. Start filling your radiator up slowly and have somebody watch the hole for the temp sensor. When it starts pouring out of the temp. sensor hole, put the sensor back in, tighten it down and fill the radiator the rest of the way up. Then fill your overflow bottle up about 1/2 to 3/4 of the way and it should purge the rest of the air and level out the overflow bottle itself. If that dont work, you have bigger problems.


One quick tip-- When you fill the radiator after bleeding with the temp sensor hole, let it sit for about 15 minutes then check it again. Most of the time it will settle by itself some. You should do this at least twice, and it should be pretty well good to go after that if it just needed to be bled out.

ok well i brought the car to 3 different mechanics and they are all telling me that its the head gasket and i found a guy to do it for $650 but what im afraid is that i heard on this site before where some guys had the actual bloc that had a little crack and that was the real main problem so would it be easy for a mechanic to see that there is a crack or not?? also do you guys think its worth it for $650? i dont know how much that usually cost. also what else should he check since he will be doing the head gaskets??

seriously thank you guys for helping me out if not i would be really stuck lol

ps. after i do this and it doesn't work just look on Channel 7 News for the guy driving his car off the pear lol

That is a very good price in my opinion, I have seen jobs like that go for 850+. The shop should have a method of testing for warpage or cracks. If not, then I'm sure they'll send it out to get checked with someone local. Since everything is apart, you might as well have him throw in some fresh plugs and wires if that hasn't been done in awhile. Depending if any coolant got into the crankcase, an oil change needs to be done, even an engine flush wouldn't be a bad idea.

out of curiosity after i do the head gaskets how long should i drive it at low rpm before i can start becoming a lead foot again lol i mean do you have to brake it in or?? also how can i check if my water pump is good?? because ever since i pit the thermostat back in it screeches a little bit so i dont know if thats a sign of the water pump. also the thermostat is a 195F thermostat but i say one for 180F and also 160F what do you guys prefer?

out of curiosity after i do the head gaskets how long should i drive it at low rpm before i can start becoming a lead foot again lol i mean do you have to brake it in or?? also how can i check if my water pump is good?? because ever since i pit the thermostat back in it screeches a little bit so i dont know if thats a sign of the water pump. also the thermostat is a 195F thermostat but i say one for 180F and also 160F what do you guys prefer?

Its not like you are having your motor rebuilt, there isn't an official break in period for a head gasket change. At least I have never heard of one. Usually bad water pumps are identified by coolant leakage from the weep hole, which is a small passage hole on the underside of the pump itself. If you are hearing noise, make sure that the pulley is tight to the pump and that it is not noise coming from another accessory ie: alternator, belt, belt tensionser, power steering pump,ect. As for the thermostat, if you change it, you will need some way in which the coolant fans can kick on sooner to take full advantage. I'm not sure how this is done on the 3.4L platform, whether it be PCM tuning or a manual fan switch.

i found that one of the pulley was lose and i also changed the belt now it doesnt screech anymore thanks for the heads up on the pulley:bow:. i just bought a 160F thermostat i didnt put it in yet but there was also a 180F thermostat i didnt know which one to get as for the fan the mechanic before had grounded it to try to cover up the cooling problem that is caused by the head gasket so now the fan just stays on all the time so i still dont know which thermostat i should put it the 160F or the 180F:confused:

also tomorrow morning im going to bring it to the machanic to get the head gaskets done so hopefully that will be the end of that problem:D

i found that one of the pulley was lose and i also changed the belt now it doesnt screech anymore thanks for the heads up on the pulley:bow:. i just bought a 160F thermostat i didnt put it in yet but there was also a 180F thermostat i didnt know which one to get as for the fan the mechanic before had grounded it to try to cover up the cooling problem that is caused by the head gasket so now the fan just stays on all the time so i still dont know which thermostat i should put it the 160F or the 180F:confused:

also tomorrow morning im going to bring it to the machanic to get the head gaskets done so hopefully that will be the end of that problem:D

I'm pretty sure GM wouldn't put in a 160 degree thermo from the factory. I would guess it would be at least 180 degrees. Easy way of knowing would be to call the dealership. Seeing that it is a thermostat, it probably is going to be a reasonable enough cost where you could probably just buy it from there as well.

well i returned the 160f thermostat ands i got the 180 and also i will bring the car to the mechanics at 8 am i hope that its just the gasket and that there is no cracks in the block:confused: so hopefully i will get it back in a few days i will let you know how it is the second i get it hopefully it will be fixed:D

well i finally got the car back and it doesnt have the cooling problem anymore :D it turned out to be the head gasket and the mechanic told me that i had a screw that was broken inside and he figured it was the old mechanic that over torqued it but anyways there is still one problem it still doesnt pick up for anything i mean if your at a red light and you accelerate to 2500 or 3000 rpm you just start to move even if im at a red light and i let go of the brakes the car stays still :( so i dont know what to check or what i should be looking at to salve this problem the engine seems great right now so i dont know what it can be:confused:

what year car is this

its a 94 3.4L one of my friends told me it seems like a loss of power in the engine?? so i dont know if it can be senors

I'm sure you are getting pretty sick of the mechanic, but it might be worth a shot to hook up a fuel pressure gauge and see what the fuel pressure is doing during all of this. How is the car running when this lack of power occurs, any stumbling or erratic behavior? How current are you on the tuneup, plugs, wires,ect. Maybe a worn out part of the ignition system, one of the coil packs perhaps. Could be a number of things.

i did a tune up about 3 months ago and i put the bosch platinum spark plugs with the four pins to create the spark and regular universal spark plug wires. i changed the oil filer and the oil last week also i put a new fuel pump and filter 2 months ago.

it would barely even move in i let go of the brakes and when i would hit the gas the rpm would go to 3000 rpm and then start to move.... i mean i couldnt even compete with a toyota camery lol but the weird part is its starting to get better slowly it seems like it is starting to have better pickup and everything. also when i would hit the gas and it would go to about 3000 rpm it would feel like if i was flooding the car with too much gas. im thinking about putting premium and also octane booster and just to run the car on the highway:confused: i dont know if that would help :confused:

octane booster is a waste of money. it raises your octane 3 points they mean 93 to 93.3
higher octane will do nothing. if the rpms go to 2500 rpm or 3000 and the car does not move you have a trans problem. it might be trying to start in a higher gear 2 or 3. sounds like it might need to see a trans shop. if you have any mechanic friends take them for a ride.

i did a tune up about 3 months ago and i put the bosch platinum spark plugs with the four pins to create the spark and regular universal spark plug wires. i changed the oil filer and the oil last week also i put a new fuel pump and filter 2 months ago.



I would stop wasting my time with gimmicky crap like Bosch plugs, but that's just me.

Bosch = great for Euro cars, bad for most everything else.

That may not solve everything--you haven't fixed the CE light/code issue--but it's a start in the right direction.

you can only produce one spark at a time. electricity takes the path of least resistance. if it hits every other terminal your plugs might last longer but a doubdle platinum will last 80000 miles. they are a waste of money

I have 2, 3400 powered vehicles, BOTH had Intake gasket leaks, GM techs here say they're notorious on these motors, they're replaced hundreds!
Head gaskets are rare, according to them.
I just finished my '01 Venture, and the "plastic" gasket was cracked by the water passage, leaking coolant into the oil pan.
The '03 Rendezvous was leaking coolant and steam, outside, under the throttle body, hard to see except just after you park.
Both fixed by replacing Intake Gaskets only.
The replacements are steel-shim with thick, chemical resistant rubber seals.
GM probably save a buck or 2 by going plastic..:rolleyes:

My Venture has a bad miss right now that I'm trying to fix too. At the top of 1st gear when it shifts and under hard acceleration...Ive tuned it up, new wires, filters, injector cleaner etc....I'm leaning towards the module.
Since I have 2 identical motors, i'll do some swaps and see for sure.