losing coolant after changing alot but no noticable leak

[tzerilli]

hey everyone,

first post I here but I have a 2004 grand prix gtp I've changed the water pump, thermostat cooling elbows throttle body gasket( the one with coolant going through it) and the person who owned it before me said he put in a cosmetic head gasket. just recently I was very hot (temps would peak at 240 with a 180 degree thermostat) and I seen my green coolant that I put in last year (flushed out dex) has turned brown and dirty so I used a chemical flush and kept it in there for two days over 100 miles then flushed that out with plenty of distilled water went through 15-20 gallons. after doing so I replaced the radiator (thicker core from Buick regal gs but basically new only 5k miles) new cap new reservoir bottle and both cooling hoses (to silicone hoses) and now im leaking the whole coolant bottle (from fill line at half way) in less than 100 miles (long trips) and I've looked and don't see any puddles near the intake and valve cover. also no coolant in oil. btw car runs phenomenal until coolant gets low then it starts to run hot but doesn't overheat only reaches about 230. never had a low coolant light just keep noticing the coolant bottle is empty help need this thing to get me to school for winter (60 miles one way) didn't leak before when it was overheating at 240 temps coolant was just brown and nasty which is weird since I changed all the coolant with green stuff about a year ago and it stayed green throughout winter

[SgtMarshal]

you are probably losing coolant driving down the highway. at least that is what happened to me.

[tzerilli]

most of my driving is highway what was the culprit for you? and what were some of the signs or syptoms or how can I test this

[SgtMarshal]

I just lost coolant, that's all that happened. it ended up being the lower intake manifold gasket and the coolant elbow's.

[rickisrad]

you need to pressure test it to try and find the leak. If none are visible I would suspect the Lower intake or head gasket. Even though it was changed it may still be leaking. If he didn't have them resurfaced to the correct RA.

[tzerilli]

I seen people do the uv dye would that help along with the pressure test also is there a way of knowing whether its the head gasket or lim gaskets before taking it apart it was after that chemical flush so im just guessing it might have loosened up an old seal somewhere and now its leaking like I said before the flush and radiator change there was no leak at all and now its crazy could it be the head in this case still I appreciate all the feedback sorry if im asking a lot school starts in a week and been doing everything in my apartment carport lol

[SgtMarshal]

if it runs fine until it heats up it's probably not the head gasket

[tzerilli]

even when it heats up it runs the same you wouldn't even notice the difference if you weren't looking at the temp gauge I just don't like saying its running phenomenal when its running hot so im assuming its not the head gasket then?? hopefully lol I even have a wideband o2 that stays consistent throughout the drive?

[Scottydoggs]

if your talking about the level in the res tank is raising and falling thats normal. why its there, why it has a hot and cold line.

your fans working? ever see if the temp matches the dash with a obd2 scanner? theres two sensors in the temp sensor, one to the dash, one to the pcm. id trust the one from the pcm over the dash.

the temp sensor is also kinda junk, they tend to fail, when they do the fans dont come on or dont get high speed. unplugging it turns the fans on full time at full speed. take a test drive like that see if the temps are lower.

[tzerilli]

if your talking about the level in the res tank is raising and falling thats normal. why its there, why it has a hot and cold line.

your fans working? ever see if the temp matches the dash with a obd2 scanner? theres two sensors in the temp sensor, one to the dash, one to the pcm. id trust the one from the pcm over the dash.

the temp sensor is also kinda junk, they tend to fail, when they do the fans dont come on or dont get high speed. unplugging it turns the fans on full time at full speed. take a test drive like that see if the temps are lower.

after burping the coolant (not bleeding it) and filling everything up all the way ive had to refill the tank twice and its empty again I cant imagine that it was running fine with that much coolant missing but maybe im not sure because I don't see any white smoke out the exhaust either so im kinda lost as to where this sheet is even going

also im using a scanforce gauge for all my readings and the fans do come on at 230 which I think is stock its just way to high for me and it does go past this if im on the gas at all when it hits 230 I had it tuned to 195 by zzp but I went to a local tuner and he said he didn't change the fan settings but that obviously changed and also my fans don't stay on shortly after I turn off the car. did his dhp somehow reset my settings or is something not working?

[Scottydoggs]

hard to say with out seeing the bin file your car is running. if the local guy just flashed a tune he made in there it might not have the fans set to a lower temp. meaning he should have read your pcm, then worked on that bin file, and reflashed it. of course i was not there, so idk what went down.

still got the zzp pcm with its tune? pop it back in if you do.

you can also pop open the t stat, fill the engine with coolant via the t stat lim hole, this will make damn sure theres no trapped air.


my old engine also ate coolant. would eat a couple inches a day. no leaks, nothing out the tail pipes i could see or smell. i dumped in a bottle of blue devil and dont ya know it stopped eating coolant. blew that engine up, new engine is 100% normal. so something was cracked inside, maybe a head or something like that. head gaskets looked just fine too.

[tzerilli]

scotty you might be right about the t stat hole come to think of it I don't remember letting it get to operating temp when I filled it and I looked up how much coolant these things hold stock and its almost 3 gallons and the radiator I put in is huge compared to stock and im pretty sure I only put in 2 gallons at most I put in uv dye and changed the cap last night going to let my dad drive it around while im at work and pressure test it just to make sure since its already in there and if no leaks im going to dump everything and make sure its filled (tstat method) also im going to visit grand rapids this weekend and if this thing has no problems im going to take it up there and have zzp dyno tune it (maybe even get some injectors and do E85) wish me luck lol and thank you again for all the advice