SOHC Ninjas: Do we ALL have overheating/head-lifting issues?
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From: Destroying turbo ITR motors in Minneapolis, MN, U.S.A.
I've been reading post after post both here and on http://www.turbod16.com regarding overheating problems with boosted SOHCs and I'm starting to see startling similarities between my problems and those of a lot of other boosted SOHC guys.
Here are my symptoms:
-first of all, I've come to the conclusion that my car only overheats when the coolant has been pushed out of the radiator (duh, but let me explain). Here's how it starts.
*Car is filled with coolant, drives fine, pulls fine, etc.
*after a few days/weeks of boosting, the temp. gauge starts to fluctuate and the car tengs to bog and not feel as powerful. So I pop the hood, surprise surprise the overflow tank is almost full.
*so I let the car cool, and pour the contents of the overflow back into the radiator, as well as a little more coolant into the radiator to replace what fell out of the overflow tank.
*also, I bleed the coolant system at that time by running the car without the radiator cap so air can come out, and a lot of air bubbles do come out every time I bleed it (about twice a month lately).
*the car goes back to being fine, I boost plenty as usual
and after a few weeks the temp. gauge starts fluctuating and the process starts over...
Now, is what I'm looking at a problem with the radiator cap not letting coolant back in, or is my headgasket blown?
Here are my symptoms:
-first of all, I've come to the conclusion that my car only overheats when the coolant has been pushed out of the radiator (duh, but let me explain). Here's how it starts.
*Car is filled with coolant, drives fine, pulls fine, etc.
*after a few days/weeks of boosting, the temp. gauge starts to fluctuate and the car tengs to bog and not feel as powerful. So I pop the hood, surprise surprise the overflow tank is almost full.
*so I let the car cool, and pour the contents of the overflow back into the radiator, as well as a little more coolant into the radiator to replace what fell out of the overflow tank.
*also, I bleed the coolant system at that time by running the car without the radiator cap so air can come out, and a lot of air bubbles do come out every time I bleed it (about twice a month lately).
*the car goes back to being fine, I boost plenty as usual
and after a few weeks the temp. gauge starts fluctuating and the process starts over...
Now, is what I'm looking at a problem with the radiator cap not letting coolant back in, or is my headgasket blown?
strangly enough run 8 psi with creep and never have any major head issues...
i can smell radiator fluid seeping, but thats only when i drive extremely hard and its been doing that for the past 20k miles on the turbo kit
i can smell radiator fluid seeping, but thats only when i drive extremely hard and its been doing that for the past 20k miles on the turbo kit
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i am consuming a lil coolant, i dont overflow it, i just consume it ... and my temp has never fluctuated, or overheated
and i only noticed it after i hooked the water coolant lines into my 14B turbo
before then (wich i ran for 3 weeks, i never used any)
i have been boosting 9 psi daily
and i only noticed it after i hooked the water coolant lines into my 14B turbo
before then (wich i ran for 3 weeks, i never used any)
i have been boosting 9 psi daily
I am also running about nine lbs. on my jdm z6 and have never had any overheating though it does get warm fast. put some arp headstuds in the block w/ a fresh clean-up on the head surface , new oem head gasket, torque per the manual except go the second time to60ft./lbs. it helped my head lifting situation!
Add me to the list of people whos car is sitting the garage busted up. 
I installed my turbo kit. 3 days later the headgasket was blown. She EATS coolant. If i drive i have to refill the radiator again.
Oh and i'm using a tiny T25 at stock boost (about 9-10psi)
I still havent found out what EXACTLY caused it to happen.

I installed my turbo kit. 3 days later the headgasket was blown. She EATS coolant. If i drive i have to refill the radiator again.
Oh and i'm using a tiny T25 at stock boost (about 9-10psi)
I still havent found out what EXACTLY caused it to happen.
Man I'm having the Same oveheating problem...Damn near to a T...I've only had mine running for a little while but I'm running lean too and can't figure it out. I'm running a WRX turbo..TD04-L it's water and oil. I'm hoping that I tapped into the wrong water line...for now I'm robbing from the lower radiotor hose and the Heater hose leading to the water pump.
I'm gonna try and tap into the other heater hose and go with the normal set up and hopefully that works for me if not I'm gonna try and go with a Better Slim fan. I'm only pulling 850 Cfm with the one I have on there now. good luck with yours!
I'm gonna try and tap into the other heater hose and go with the normal set up and hopefully that works for me if not I'm gonna try and go with a Better Slim fan. I'm only pulling 850 Cfm with the one I have on there now. good luck with yours!
i was boosting 8psi on the d15 no overheating problems blew cause of other reasons. now boosting 9psi on the d16 for more than a month and havent had any overheating problems. but the d16 did have a bad headgasket when i started it up was leaking coolant out through the exhaust manifold,put a new one and still no overheating problems.
btw T-RO get a helms manual, borow or buy a """"""good""""" torque wrench and install the headgasket yourself its pretty simple and strait up , and take the head to the machine shop to have it resurface.
btw T-RO get a helms manual, borow or buy a """"""good""""" torque wrench and install the headgasket yourself its pretty simple and strait up , and take the head to the machine shop to have it resurface.
I am also having the overheating, coolant coming out the top of the overflow tank issue. I guess I will try torquing my ARP's down a little bit more. It was fine when the motor was freshly put back together, but now that she was beaten on for 500 miles or so, she starts to overheat after a few hard pulls.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Pfieffdog »</TD></TR><TR><TD CLASS="quote">I am also having the overheating, coolant coming out the top of the overflow tank issue. I guess I will try torquing my ARP's down a little bit more. It was fine when the motor was freshly put back together, but now that she was beaten on for 500 miles or so, she starts to overheat after a few hard pulls.</TD></TR></TABLE>
yeah, mine was pretty much fine for about ~6,000miles then it wouldn't stop spraying coolant out.
Anyone that is having this problem running a blockguard? Mine was only sitting about 2-3mm or so down in the block and just kinda snug. I didn't want to force it down too much. It's a race eng. one. I'm wondering if maybe it lifted up too.
yeah, mine was pretty much fine for about ~6,000miles then it wouldn't stop spraying coolant out.
Anyone that is having this problem running a blockguard? Mine was only sitting about 2-3mm or so down in the block and just kinda snug. I didn't want to force it down too much. It's a race eng. one. I'm wondering if maybe it lifted up too.
well before i installed the turbo the fan never came on due to putting red-line water wetter in. but with the turbo it fan comes on and off like normal. so yea it got alittle warmer. im not sure other peoples opinion on this but the water wetter works great
Just picked some up and tomorrow I'll be running my water lines off of both Heater hoses....hopefully that works...right now I'm robbing it from the Lower Radiator hose and from right before the thermostat (heater hose) on the right...
this is an interesting thread. i have noticed that my overflow reservoir is a little above the max full, and i cant recall if it was below full when i started boosting. my headgasket only has about 20,000 miles on it, but the headbolts were reused at least once, which sometimes doesnt sit well with me. ill have to keep an eye on this...
boostincoupe this has been an ongoing problem for you i take it , we have talked about this in other posts . you have other issues going on im sure , like a warped head or block , slightly cracked sleeve , even the smallest tiniest nick or cut in the sleeve will cause that . i had that problem and a thicker cometic firering gasket cured my problems along with arp head studs . might want to check into that.
i just got my sleeved built block back from AEBS , and i asked for it to be o-ringed , it wasnt because i guess they cant o-ring the d series sleeves or somthing . that would have guarenteed me no issues . oh well , i hope i dont have any issues.



