DanielRicany

No Spring In The Hose. I Used Fel-Pro 1205 Intake Gaskets, Fel-Pro Thermostat Gasket, And Chevrolet Performance #10105117 Head Gasket.

856SPEED

I thought you fixed it??



http://forums.corvetteforum.com/c4-t...t=danielricany

I run AFR/TPIS heads......it's not the heads......

This may be the problem......

http://forums.corvetteforum.com/c4-t...t=danielricany

rocco16

While you won't hurt your engine by turning 4000rpm under no load, doing that has no basis in the real world. There is no logical reason that I can think of to do it.

Cruising at 4000rpm?? You'd have to be cruising at well over 100mph AND/OR be in a low gear to be turning that much. Both situations are as unusual as holding 4000rpm for an extended period of time under no load.

Does your car overheat under NORMAL circumstances??

I would NOT install a 160 degree T-stat. I wouldn't even install a 180 degree T-stat. Your car's engine controls system was designed to run at higher temps and will run best at design temps on the street.

856SPEED

Or this thread was equally concerning.........

http://forums.corvetteforum.com/c4-t...questions.html

DanielRicany

I fixed the leak by using a different gasket. I also believe I may have used thread locker instead of thread sealer on the head bolts the first time around. Also, I fixed the other overheating problem, where it would overheat just driving around normally around town or on the highway.

Well they technically are normal conditions for me. I have 3.75:1 in the rear. 70 mph in 4th gear is around 3,000 RPMs.

BOOT77

I had a friend who had problem with his pump impeller spinning, but only when it got nice and hot. It would expand just enough too slip, he even pulled and checked it, cold it was nice and tight. Wasn't until he boiled it in a big pot and checked it he found the flaw. Your pump could have been flawed but still cooled enough before the upgrades. Sometimes you just gotta keep trying till you find it and it could be something you'd never thought of causing the problem. GL hope it's the pump.

c4cruiser

Running that high RPM while the car is sitting still is asking for high temps. Even with the fans running, there is very little airflow going thru the radiator. Low airflow=overheating.

You are now saying you installed an "old" water pump. How old? One year? Two? 10 years?

Not having a spring in the lower hose should not be an issue assuming the hose is new. If you can find a hose with a spring, then I would suggest you buy one and keep for a spare or install it and keep the other hose as the spare.

Again, pull the current water pump off and inspect the impeller. Look for correct rotation and/or any wear on the blades or if the impeller is not moving water in the right direction.

I watched the video you shot of the serp belt tensioner and yes, they will jump around when the throttle is opened quickly. But if that spring is weak, the jump will still happen and once RPM stabilizes, there is a chance the belt will slip on the W/P pulley. W/P pulley slipping=overheating.

Do this check and if you still have concerns, install the correct water pump before diving into the heads. I don't think you have any issues at all with the heads.

DanielRicany

If I'm not mistaken, the previous owner may have replaced the water pump less than two years ago. Also I replaced the tensioner about 8 months also.

cv67

Is your deflector under the car in good shape not all worn down that will make a difference

Get it wired right
If its running non stop esp on the fwy although it may not be THE problem it can heat things up
The incoming air needs somewhere to go if the speed is greater than the fans. If the fans are always on hello heat.
X2 on ckg the water pump impeller. Its something simple that youre missing just gotta dig into it. Bet the heads are just fine.

Maybe you could ask Tony about what we think.

Second thought scratch that

DanielRicany

I hot wired the fan previously when I had the other overheating problem, which proved the point of it not being insufficient air flow through the radiator. And yes my air dams are in place.

cv67

When the lower hose sucks shut you may not see it happen from just revving it up may need to be held there for some time, happened to me. Had the wrong type of radiator cap on it.
You can buy springs on ebay they are stainless

are you still running the stock fan(s)?

0Tony Mamo @ AFR

Guys,

A forum member alerted me about this thread.

Long story short I have been speaking with this customer since March and have had many emails with him.....a few of them responding on weekends, evenings etc. I have invested a good deal of time trying to help Daniel sort through all of this and never gave him the impression that AFR would not stand behind the product in the event he had an issue related to our heads which is certainly a possibility. During that time I received a few emails from Dan stating he resolved the problem or found a situation that might have.

This one from 3/28

This one on 3/31

I wont lie, it got to the point I was more questioning the install and/or some of the components than the actual heads but during this time I clearly conveyed to Daniel that we (AFR) will gladly look over the heads and evaluate them for proper water flow. While extremely rare, occasionally there is an issue at the foundry where part of the water jacket can be blocked off due to issues with the water jacket mold when they poured the casting. Its rare but it happens and visually you cant see anything wrong unless you literally cut the head in half so you can examine all the water jacket passages.

Ultimately when dealing with a situation like this its always best to cross all your T's and dot your I's prior to removing the cylinder heads to avoid alot of extra work in the event it was something silly (a kinked rad hose, bad water pump impeller, faulty thermostat, issues with electric fans or the radiator itself.....etc. etc. It would be a crime to have removed the heads without being confident all the other components in the system were functioning properly. Also, a cooling system that might have been on the ragged edge at 300 RWHP might not be up to the task of cooling an engine making 100 HP more.....power is heat and it needs to be shed.

My goal was to help figure out if he had other issues potentially causing this and Daniel himself admitted he didnt want to pull the trigger too quickly on labeling the heads as the problem.

Also guys.....nothing wrong with running a performance engine at cooler water temps. Hot oil and 160-180 degree water temps make power.....less underhood heat baking all the induction components for a denser air charge.....motor less prone to detonation etc. Running an engine close to 200 degrees reduces emissions ever so slightly....no performance benefits whatsoever.

Daniel.....if your confident you have exhausted all the effort you want checking other potential problem scenarios by all means lets pull the heads and have you send them in for evaluation. If there is a water flow issue with the heads we will either fix or replace them, cover all your freight, and send you new head gaskets as well. You would need to contact me prior to sending them in so I could assign you an RMA number.

You know how to get in touch with me

Thanks,
Tony

WW7

Daniel, My suggestion is to replace the waterpump,( it's ordered already, might as well put it in) put a spring in the hose, to stop any collapsing problem you may have, and see what happens....That may be all you need....WW

DanielRicany

Thanks for the response, Tony. Rest assured I am not upset with you about anything, and I am thankful for your time and advice helping me through this!

ynot d

I have seen overheating caused by setting the timing too far advanced. (initial)

dizwiz24

daniel

Is there any chance that you are pressurizing your coolant? By getting exhaust bubbles into your water jacket from bolts or head gasket that is not sealing?

Its easy to check, just look for bubbles in the radiator Fluid while you are idling it (cap off). Might want to try a range of rpms.

Is the car using/losing coolant?

I was told a zillion times to be sure to run thread chasers, brake cleaner thru the head bolt holes (must pull out the knock sensors to drain all of that nasty solvent mess out) and then use thread sealer on the head bolts.

I havent had any over heat issues on my afr 195 for ltx and i also happily run the 160 tstat. That, with reprogrammed fans, makes the car run 175f or less.

Lloyd Smale

If your crusing at 4k in 6th or with an auto going to jail is going to cost you more then getting your motor cool. If your not in 6th i have to ask why you would cruise in a lower gear?

dizwiz24

Uhh...he is attempting to diagnose a problem where rpm may be a factor.

powerpigz-51

His symptoms relate to a combustion leak into the coolant. Someone with an emissions wand needs to take a sniff at the cap. Napa also sells a chem test.

cumbercr

If the water pump turns out to be a non problem, I would lean toward the head gasket. The fact that the problem only occurs at high RPMs lends some credence to a leak that only shows when cylinder pressures are at the highest.