radiator overflow filling up quick...after agp turbo kit, ect. install

[PaulN]

Well the coolant is a 50/50 store bought mixture and is completely new from the engine swap two weeks ago.

I'm not entirely sure about the other question of whether or not the thermostat gasket is leaking and running down the hose to the overflow. One thing that makes me think that's not the case is my car sits on an incline with the nose higher than the rear. I guess It's possible. I'll investigate this issue further.

Thanks for the look and suggestions!

 

[PaulN]

Went out at lunch and took the pressure cap off the thermostat housing and started the car up and let it run.

I was looking to see if the antifreeze was gurgling at tempurature. I read on the internet if you have exhaust gases getting into your antifreeze you should see it gurgling/bubling over/creating a geyser with the pressure cap off.

It wasn't doing any of the above.

As a matter of fact, I put the cap on and I can't duplicate any of the symptoms now.

So, here's the theory for now. I have one of those caps that has the pressure release levers on it. I am not sure if it was loose or raised or what. I don't remember, but I can tell you it didn't feel like it was latching down correctly. I wonder if it was up allowing all that pressure to push all my antifreeze into the overflow? Just a hunch, but I bought a "normal" cap that doesn't have any pressure relief levers during lunch and will swap it out tomorrow morning before I start her up and see what's what.

Everything else looks normal. No cracks in the resevoir, no noticeable leaks, or anything.

 

[Staytuned]

There is only a few things that can cause this problem....bad rad cap, head gasket shot, bad water pump (causes over heating) and over filled coolant reservoir or cracked reservoir. Other than getting into more serious stuff like cracked head or block these should solve your problem.

 

[PaulN]

Well, It still hasn't done it again. I replaced the radiator cap so I don't know if that was the problem or not. For now, I am gonna blame the cap. I'll post back if something changes.

 

[tsiawd98]

Ok my problem is that im leaking coolant out the overflow bottle only. I have searched the threads and found 2 possible causes, my pressure cap isnt strong enough, or I have a blown head gasket.

Ill start out by saying that this is a new eng., new head, new cometic HG., thermostat, waterpump, fluyidine radiator and hoses. and Im on 1500 miles on the eng. About a week ago I noticed I started leak coolant out the overflow bottle. So i searced and found out I should get a 16 lb pressure cap for a 300z. Well It was still doing it, so next I did a compression test on it and had 150-155 comp. on a cold engine. the car also never overheats at all. And I have to continuosly put coolant in the system after a good long drive.

I made sure all the hose clamps are tight and still I continue to leak coolant out. the only possibility I can think of is a crack in the head. witch i shouldnt have cause Im only running 12lb of boost on a 3065 with a new head job from polk performance with virtually no knock whatsoever. Im looking to see If anyone can pinpoint my problem for me please. any inputs would help alot.

 

[1stGenRocks]

It might seem like a dumb question but are you sure your filling it to the right spot? If the coolant bottle is too full then it will overflow when the engine warms up.

 

[tsiawd98]

Yes I fill it up where you take off the pressure cap. Then when i go driving it leaks.
When I go to drive again theres usually no coolant in the thermostat housing area where the pressure cap is. thanks for input

 

[Newlogics]

Ok my problem is that im leaking coolant out the overflow bottle only. I have searched the threads and found 2 possible causes, my pressure cap isnt strong enough, or I have a blown head gasket.

Ill start out by saying that this is a new eng., new head, new cometic HG., thermostat, waterpump, fluyidine radiator and hoses. and Im on 1500 miles on the eng. About a week ago I noticed I started leak coolant out the overflow bottle. So i searced and found out I should get a 16 lb pressure cap for a 300z. Well It was still doing it, so next I did a compression test on it and had 150-155 comp. on a cold engine. the car also never overheats at all. And I have to continuosly put coolant in the system after a good long drive.

I made sure all the hose clamps are tight and still I continue to leak coolant out. the only possibility I can think of is a crack in the head. witch i shouldnt have cause Im only running 12lb of boost on a 3065 with a new head job from polk performance with virtually no knock whatsoever. Im looking to see If anyone can pinpoint my problem for me please. any inputs would help alot.

Yep, it's your HG.
We had virtually identical scenarion on our shop car. Only 5K miles on cometic HG. Although in my case, this was caused by a trottle body shaft giving it, and feeding a small bolt to number 1 cylinder.
At first we thought that we got lucky and bolt has 'passed' through the system without consequences, but then car started loosing coolant through overflow bottle. Never overheated, just blew coolant. We tried new cap, waterneck, thermostat and god knows what else. Simply because I refused to admit that it's the HG.

We eventually pulled the head and found leaking spots. Not pretty, but fixable.

 

[sweet97]

Paul could be right that it's the head gasket but before I pulled the head I would add fluid to the overflow bottle and not the pressure cap. Keep the system sealed. Do you ever see the coolant come out the overflow line?
My car also looses fluid after a long hard drive. My head gasket is fine. Probably could use a better cap.
Seems you are not filling the coolant correctly. Fill the overflow bottle to the cold line and drive it some. When the fluid cools if the motor needs some it will draw it from the bottle and then add to the bottle.
I would hate to see you pull the head for nothing. Check the comopression on a warm motor too. Just trying to save you from pulling the head. Hope you don't need to! good luck, Mark

 

[oddrob]

Just a side note, but I have not had very good luck with the Cometic head gasket. They have head gasket leak detectors that you could pick up, they don't seem to be 100% but it might lead you in the right direction.

 

[tsiawd98]

If it is the headgasket Ill change it, but im never getting another cometic. where do people get the HKS HG? ### I heard thats a good one to get, and witch one.

Yeah I already filled the overflow bottle and coolant system and it still leaks, so looks like ill be doing a HG job on a new Fxxkin Eng!! Ill do a another comp. test while the eng is hot and see what it does. But thanks for giving me these inputs.

I also just started the car up with topped off coolant and with the pressure cap off and immediatly when i started it the coolant started to come out of the water neck? So I guess ill go to napa and get one of those strips to test hydrocarbons in your coolant and get an answer?

 

[Newlogics]

The answer is pretty apprent, but it's always good to know for sure.

As for the HG, why not Mitsubishi MLS?
In two years I've ran the shop, we've installed over 50 of those, and not a single one failed yet. Be it 200hp engine or 500hp... That gasket is great and compared to HKS and Cometic, it seems like way better value.

 

[GSntncT]

As much as I hate to say so, especially with me having this issue twice, they may be right in saying its a hg.....

I'm pretty sure you've gone through it all, but did you check for any water in the system? Did you check your heater core? Those were the issues that led to me blowing my last gasket.

Hope it's something minor.

 

[1LE]

I've had that problem twice. Once it was the seal in the cap on the overflow bottle (I like to corner hard, and I guess it was enough to get it leaking out up there). The second time, the overflow bottle developed a small crack in the side...

 

[tsiawd98]

I bought the new HG and will be replacing it soon. It just sucks ### its a new eng. but thanks for the inputs it helped me out alot. and hopefully I can finally tune this money pit by the end of next week.

 

[girlieracr4g63]

If you havent already done so. A set of ARP's wouldnt hurt. Also makes it a hell of alot easier to pull the head in the future.


Wendy

 

[tsiawd98]

I already have the ARP's on the shit box. but thanks

 

[GVR4592]

The surface of the cylinder head has to be very smooth or any steel gasket will leak. This is the most common problem with steel head gaskets. The surface needs to be 50 RA or better.

 

[steve-o_95_GST]

The surface of the cylinder head has to be very smooth or any steel gasket will leak. This is the most common problem with steel head gaskets. The surface needs to be 50 RA or better.

Does this apply to the deck of the block too? Mine isnt shiny but my machinest said it will seal a mls just fine. It feels smoth and everything but im not sure if its good enough. How do you find out the RA?

-Steve

 

[NewB2dsm]

I had my competic fail on me to. Head was decked and preped block was just preped. After about 25passes at the track and then some detenation when the evo16g crept up on me it went. Cant blame it but this time around i did spray a very small amount of copper gasket sealent on it.

 

[GVR4592]

The head and the block have to be 50RA or finer, or it will not seal. Most machinists don't have a clue when it comes to steel gaskets, they assume that the finish is good enough but they really have no idea.

 

[johnfsmith]

I had this problem too... this may sound dumb but my problem was with the FMIC and relocating the overflow bottle. I mounted the overflow bottle too low, I moved the bottle up to stock height and it fixed my problems.

 

[girlieracr4g63]

I have always had good luck with the 4 layer mitsu, and ARPs running 24-25 psi.On both my awd and fwd. Also from what Ive heard the cometic and ones like it work best on brand new engines.

Are you sure the coolant is recirculating? Just an idea.


Wendy

 

[AnkurJ0217]

Here's my problem. I have to fill up coolant in my dsm every week or after i go for a long highway run. The pressure in the cooling system builds up too high and sends all of the antifreeze into the overflow tank. The overflow tank over filled and starts to spill into the street. I replaced the radiator cap with a new 13 lb pressure cap (oem recommendation) and it still does this. I am stumped at what could be the problem. There is something causing my car to heat up alot and i definitely do not have a misfire. I replaced all my plugs and wires and the car runs beautiful under WOT. Car does have an idle problem and it is missing the bliss screw. The SES light is not on because the car runs fine. Just this one problem with the cooling system. I hope it is not a water pump issue (A lot of time and work on my part). Any ideas of what could cause this?

 

[Mike Marnik]

it could be your thermostat also. I would change that out and see what happens. Its easy and cheap to fix.