Probably head gasket material. I have the same issue currently. Gonna pop the head off here soon.

 

how fast is your overflow filling? does the level go back down after cooling or just stay full?

Looks like the only other test would be a leakdown test to see if im getting air bubbles in the radiator while performing the test.

 

Stays for a bit. I pour it back when it gets cool enough to pop the cap off. Its not losing any.

 

Everything these guys are saying is entirely true. I'd just like to add something simple:

Slow down on messing with the coolant level constantly. Need to find a static base line. I'm a diesel tech and multiple times a day im draining coolant systems and vac'ing and refilling for various repairs/reasons.

Car dead cold: Put a small amount in your resevoir, top off rad. Run engine until fan kicks on, crack bleeder at tstat housing if you have one. Repeat. When you think your done do it again. Shut it off. Leave the car cool over night. As your coolant cools down, the level will drop. After the car is dead cold (overnight if thats easier) I would fill your resevoir to a good known level, maybe halfway between low and max full, mark it if you wish with tape or a sharpie or both. We are now at your baseline. Now if you start pushing, leaking, burning what ever your going to know it for sure. Dont go topping it off after a drive while its still hot or emptying it while its hot, your throwing it all off. Coolant will expand and contract, hence the overflow resevoir.

When I vac fill systems at work, I topp it off at max level. Run the truck until the fan kicks in, park it. The level is usually over max. Ill check the unit the next day if its still in the lot, and 9 out of 10 times I need to add 1/2-1 gallon (13+ gallon systems).

Dont know if this makes sense or not.im typing on my phone right beforr bed so forgive my typos and possibly off base suggestion. You need to absolutely confirm you have trh correct amount of coolant to start or you may be chasing your tail. All the suggestions these guys have givem are very possible and likely. Just wanted to add my 2 cents.

 

Hes got the bleeder type funnel system that works pretty darn good at bleeding it all the way the first time.

 

Took the car on a 1 hr drive (45 min highway (75mph)) car ECT sat at 205 after 10 min on the highway. Did two 4th gear pulls and and one 4th and 5th gear pull during 45 min on highway part stayed at 205, cooled to 185-190 with fan on after getting off highway. Got to work and coolant bottle was 90-95% full. performed the block test again, and again it comes back negative the test fluid doesn't change colors after over a minute of testing.

I then noticed a small paint rub on my hood above the radiator cap, i then pulled and pushed on the cap with my hand and noticed bubbles coming out of the overflow, unfortunately i didnt look hard enough to notice if it was bubbling before i touched the cap.

Ill be letting the car cool for 5 hrs, and then assessing the overflow and radiator levels, then driving it back home.

 

Bro...don't ever open a radiator cap after driving it...dangerous ****. How's your water pump?

 

Never opened it, that would be a big no no. i pushed and pulled on the ears of the cap, which is when i heard the bubbling. the pump is a 2k mile old oem honda pump.

 

Emptied the overflow back into the radiator, burped the lower hose a few times and hit the road. ECT got up to 208 on the highway at 80 degrees outside. Did zero pulls and minimal boosting at all. Overflow filled to the same spot.shut the car off, No bubbling. i pulled up on the edge of the radiator cap again and it started bubbling in the over flow.

Just got a leakdown tester. should have some results this weekend.

 

Who tuned your setup? You could potentially run into overheating issues if the tune is not properly done, so I've heard.

 

I believe its too much timing that can cause higher temps due to the combustion process happening earlier. Not really an AFR issue but timing does effect cylinder temps

My car was doing this last month same time you originally posted, Since I have pulled the head to reinstall gasket with copper spray this time. I also upgraded my radiator to a mishimoto 3 row and decided on a pusher fan (spal 1360CFM).

Originally I had a puller fan (chinese) with shroud, and skunk2 radiator. My car now runs 10 degrees colder at all times, after some freeway pulls I was at a 194, pulled up to a stoplight sat for about 45 secs and It was back down to 190.

I did change a few things but Im pretty sure your in the situation I was in last month I say headgasket is bad by now and the major problem is skunk2 radiator just does not seem to work well on boosted setups

 

I wouldn't jump to that conclusion quite yet. I've experienced quite a few skunk2 radiators to the contrary of your beliefs

 

yea not sure if i had a bad head gasket possibly that was the only problem, but the gasket had less then 500 miles on it. I was having the same kind of temps hes having..... 205 after 10 mins on the freeway. Everything works good now I changed radiator,fan and head gasket

 

The car was tuned by Jeff Evans.

I did a leak down test over the weekend, Jeff recommended i do it with the engine cold to help expose a bad headgasket. I got between 10-15% on all cylinders, with no bubbles coming out of the radiator neck. I even put 80psi from the compressor straight to the cylinder and got no bubbles.

However the coolant i put in the funnel to make seeing the potential bubbles easier, came from the overflow bottle and was full of these black specs.

 

Which is fine. But you can't change three things that are all essential to the cooling system, and then pinpoint the issue as being just one of those components, just because you "guess so".

You've basically eliminated the clues that are necessary for a diagnosis of a problem by replacing all of them. This is presuming of course that proper installation was the same each time.

 

Did you ever completely clean out the overflow bottle BEFORE re-doing your tests?.. you obviouslly had a clean funnel, so, perhaps the entire system needs to be flushed and cleaned

 

yea, i had previously replaced the overflow with clean liquid. At this point the only thing left is the hood touching the radiator cap. i cut the webbing and made it clear. I will bleed the system once more and drive the car on another hr long cruise and see what happens. If it still pushes over, i have got to believe the black specs are head gasket material and it has a small leak under hi temperature, as i have idled it for 2 hrs without it overflowing.

 

I gave him some possibilities Im not trying to diagnose his motor over the internet, seriously this is an open forum let others have input, if you have input also thats fine but dont try to prove everyone wrong all the time its like your one of those ppl that always has to be right, and prove others wrong to feel better about yourself

 

But more often than not, he is right.

 

Lol yeah but he can give his opinion without being a dick about it. I never challenged his opinion, I only gave my opinion

 

I'm not challenging your opinion. .my opinion isn't the only one that can be correct. Im not trying to be right just to prove you wrong. .that's a silly way to look at these forums.

I'm only challenging the way you're going about finding your conclusion. It's the thinking that I'm challenging your brain with, not the opinion or ethics.

Carry on with what you want to say, you're just fine, sir..

 

I just wasnt happy with my skunk 2, didnt seem to perform well under harsh conditions. my mishimoto definetly has a higher fin count then the skunk2 did.

and then theres this:

Which tells me your not a big fan of the skunk2 either

 

I give Skunk2 a 3rd place after Koyo & CSF.

Mishimoto is rather last. .

There's more to a heat exchanger than fin count.. MUCH more.

 

damn wish I had known about CSF I prolly would have gone with one of those had I known.

I havent personally dealt with Koyo, but alot of people are saying the quality has gone down since there no longer made in japan

 

Nah.. at least not with my exposure with them over the last 10 years.

There's also a facility in Plymouth, MI