347 RUNNING HOT

Zeffer

Member
May 27, 2020
43
19
18
Mission B.C.
Hey everyone, I'm almost at the end of my rope here...

A little background to get us started.

I have a 1989 hatch with an AOD, a/c and 4.10 rear gears. I live in Mission B.C. Canada, for those of you that don't know, we are about 3 hours north of Seattle, our weather is very similar to theirs. I have rebuilt the engine myself using the Scat 347 kit, it has PW aluminum heads, Comp cam, 70mm BBK throttle body, 24 lb injectors, Edelbrock intake, pretty standard 347 build. I'm running a Holley Terminator X system. I have the base tune that came with the Holley loaded with a few tweaks I learned from Leech Motorsports. I have a SVE aluminum rad with the Mishimoto dual fan setup, one set to come on at 185 and the other at 195, 190 degree thermostat, stock pullies, all radiator air deflectors are in place and am running a 50/50 coolant mix. I have made sure there is no air in the cooling system by having it jacked up to the sky in the front and running the car, left the rad cap off until the thermostat opened and then installed the cap. I have rebuilt the transmission myself, it has a Lentech valvebody and a 3000 stall non lockup convertor, I've added an aux. trans cooler in front of the a/c condensor. If I start the car and let it run, the temp will climb to about 190-195 and maintain this no problem. When I drive the car the temp will climb to approx. 220 degrees, I've confirmed this with a laser temp gun. Today when I drove it, the temp climbed to 222 according to the Holley, the ambient temperature here today was about 21 C or 70 F. I must have enough cooling system capacity to keep this thing cool!
Looking for any ideas from this awesome group...
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nice build, now if those fans are pulling good cfm's, the water pump is working then you probably still got air in the system.
i have got the lisle funnel set from amazon and got all the air out of mine, i daily mine with a/c on in the desert heat for many many years always stays 200 or under.
 
I think it's the fans. My turbo 347 stays below 212° even with hard pulls with a 195° thermostat.

Keep in mind that timing can affect engine heat. What is your base timing set at ? I still believe it's a fan issue but curious on your base timing. The timing curve can have a lot to so with heat. Especially if it's leaning out as rpms climb.

The Contour fans are ugly but they work amazingly.
 
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I dont think its the fans I Know it is. Throw those fans in the trash where they belong, they are your issue.... Stock or pretty much any oem electric fan will cool better then that junk. Its designed to look pretty, that's it. Those cheap china fan/shroud combos can't even keep up with a stone stock a/c car and no I'm not joking, they block flow..... I honestly wish the specialty shops would stop selling that crap as a performance upgrade, its not, it just a high profit polished pos meant for show cars that don't get driven.

Buy an oem or repo contour fan if you want the easiest route, I like some of the newer brushless stuff that you can get from any pick an pull dirt cheap but most people don't know how to wire a PWM fan into an older car.
 
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I dont think its the fans I Know it is. Throw those fans in the trash where they belong, they are your issue.... Stock or pretty much any oem electric fan will cool better then that junk. Its designed to look pretty, that's it. Those cheap china fan/shroud combos can't even keep up with a stone stock a/c car and no I'm not joking, they block flow..... I honestly wish the specialty shops would stop selling that crap as a performance upgrade, its not, it just a high profit polished pos meant for show cars that don't get driven.

Buy an oem or repo contour fan if you want the easiest route, I like some of the newer brushless stuff that you can get from any pick an pull dirt cheap but most people don't know how to wire a PWM fan into an older car.

These are pretty much the fans I always recommend for a dual 12in setup on a factory width radiator. The advertised rating isn’t the highest, but that’s not the only thing that effects output. Usually what I’ve seen though if the car doesn’t overheat sitting at idle for extended periods then it’s not the fans though.

When burping the cooling system, I like to rev the engine up a good bit to speed coolant flow up, seems to make the level drop some. Base timing is good to verify too, that’ll make a good difference. Also, you said all the deflectors are in, but just to confirm; the lower air dam is there right?
 
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I've definitely read that some of those cheaper fans pulled less than the oem one(s). The ford contour fans work fantastic, just a little expensive if you have to buy the relays and fan controller as well. I think all said and done was about $350 for myself. Also what Karthief mentioned about the fans going in the correct direction would make a world of a difference if they were incorrect.
 
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nice build, now if those fans are pulling good cfm's, the water pump is working then you probably still got air in the system.
i have got the lisle funnel set from amazon and got all the air out of mine, i daily mine with a/c on in the desert heat for many many years always stays 200 or under.
I have built many engines in my life and have never had any issues with air like a lot of people suggest here, I've always filled them, and ran until the thermostat opens, adjusted level, closed cap and call it done. However this is my first 5.0 build....done a lot of 460's and Cummins ISB and Detroit engines.
What cfm do the fans pull?
Are they turning the correct direction?
Have you verified the thermostat opens at the right temp?
Have you tested the fans for low and high modes?
I'm not sure of the cfm, but this setup is specifically for a 5.0 Foxbody application, they are turning the right direction and my thermostat is openining at 190. Fans only have one speed, both are controlled by the Holley.
I think it's the fans. My turbo 347 stays below 212° even with hard pulls with a 195° thermostat.

Keep in mind that timing can affect engine heat. What is your base timing set at ? I still believe it's a fan issue but curious on your base timing. The timing curve can have a lot to so with heat. Especially if it's leaning out as rpms climb.

The Contour fans are ugly but they work amazingly.
A lot of people keep saying it's a fan issue, driving down the road with airflow, the fans shouldn't play as significant a part in cooling the engine. When I have the car running in the driveway, it will maintain 190 degrees,
My base timing was set at 10 degrees and confirmed in the Holley.
The Holley should be controlling the engine to prevent a lean condition, I also have a wideband gauge and haven't noticed any excessive lean numbers.



I was thinking last night about the possibility of the transmission fluid increasing the coolant temp as it goes through the rad first and then to my aux, cooler? I rebuilt the trans myself and although it seems to shift ok, I've never done one before and an questioning myself, I do have a 3000 rpm non lockup stall convertor in it.
The other thing I was thinking, and I hope this isn't the case, is I **** up and installed the head gaskets wrong restricting coolant flow out of the engine

Thank you all for your input, I know there are a lot of smart guys on here willing to help and I look forward to any comments
 
I forgot the most important part to my problem......
After I rebuilt the engine, I was still running a stock rad (less than a year old) and an oem clutch fan with underdrive pullies and it was running hot as it is now.
This is when I decided to upgrade to the SVE rad/electric fans and ditch the under drive pullies.
 
First let's address the fans, just because it says it works for a fox body or whatever car body, you need to know what the cfm is, also the lack of high speed mode is a concern, the shroud plays a large part with air flow, some of those shroud designs can actually restrict air flow at speed, air can 'pack' inside the shroud pushing the air around the front instead of through.
Reading your last post would tell me there is a flow problem after the radiator, insufficient flow possibly from water pump or a lower hose collapsing.
 
First let's address the fans, just because it says it works for a fox body or whatever car body, you need to know what the cfm is, also the lack of high speed mode is a concern, the shroud plays a large part with air flow, some of those shroud designs can actually restrict air flow at speed, air can 'pack' inside the shroud pushing the air around the front instead of through.
Reading your last post would tell me there is a flow problem after the radiator, insufficient flow possibly from water pump or a lower hose collapsing.
General, the overheating was present before I switched to the electric fan/shroud combo, the water pump is a new Motorcraft one. The fans are only on or off there isn't high speed, the description states they flow 2300cfm, I'm assuming that's combined? I'm going to change my settings on the Holley to have both fans on at 190 and see if that makes a difference.
What would cause the lower hose to collapse?
 
You can buy the aftermarket contour fans for as little as $70, depending how you want to wire it maybe $50 more.... Junk yard oem fan, pwm controller and high amp relays I never was charged more the $50 from a you pull it.. The x can control a pwm fan if you have a free output.
A lot of people keep saying it's a fan issue, driving down the road with airflow, the fans shouldn't play as significant a part in cooling the engine. When I have the car running in the driveway, it will maintain 190 degrees,
The shroud on that fan set up blocks airflow, it literally does what truckers do in the winter with below zero temps to build heat except they use cardboard... I've swapped probably 30 of those fans out because they where the problem..... Just because a company sells you something as a performance product doesn't mean it is. The brands who sell those does JACK :poo: except mass market Chinese junk.
 
Lower hose collapsing is caused by either a weak/soft hose or restricted flow.
raise the rpms while watching the lower hose, if there is a problem you will see the hose flatten out.
The fans are puny in the cfm department but should be sufficient (barely) slepping around without the ac, now a question and a suggestion, where is the temp probe for the temp reading for the Holley?
Get a mechanical temp gauge with the probe in the stock location, take the guess work out of it.
You stated the air damn is under the radiator right?
Also, just to eliminate a variable, run the outside trans cooler only, not through the radiator cooler.
 
Here are some thoughts:
  • Have you pressured checked your cooling system? I had a 460 with a head gasket on it's way out that would get hotter and hotter the longer I drove it. The head gasket wasn't bad enough to show up in a leakdown or compression test, but it was the culprit. This happened with any ambient temperature, it just look longer to happen on cooler days.
  • Do you have the air dam in place? Is it solid and not cracked or flopping around?
  • Can you pull the fans / shroud and cruise around without any radiator restriction to see if there is any difference in temperature? (This only works if you can avoid extended idles / stops at traffic lights.
  • Have you pressured checked your cooling system? I had a 460 with a head gasket on it's way out that would get hotter and hotter the more I drove. The head gasket wasn't bad enough to show up in a leakdown or compression test, but it was the culprit - the cooling system had a pressure leak.
  • Have you replaced the radiator cap?
  • You mentioned that the base timing was set at 10 deg BTDC; was this checked with a timing light? (You can't trust the ECU since these cars don't have a crank position sensor, so the timing is relative no absolute. Even if you add pickup wheel on the crank, it may not be 100% correct and needs to checked against the physical spark timing.)
  • Is your temp sensor located in the intake manifold upstream of the thermostat?
I sincerely hope one of our suggestions get you to the root cause. Temp issues drive me crazy!
 
When my fan wasn't powerful enough it would spike hot right after being up to highway speeds. Back then it took a long time to figure it out.

I was going to mention all the air dams around the radiator but I believe you stated they were all there.

In order for the transmission cooler to transfer that much heat it would have to be way beyond the normal temp limit.

One of the head gaskets could be backwards but they usually are cut the same...unless it had block offs at the rear ports. You could probably use a stiff wire and check the passenger side through the thermostat opening. ( I've never attempted it )

There has been a bunch of inferior designed aftermarket water pumps that have popped up on here over the years. We had a guy that had an overheating problem and it was because the water pump blades were too short causing cavitation in the coolant. I believe it was a name brand high flow one. Some have even found the impeller just spinning on the shaft.

You can check the flow by putting a 3/8 npt barb fitting in the temp sensor spot and running the car with a hose in a bucket. When you start it cold the thermostat is closed directing more fluid out.

The lower could be collapsing. I have a metal lower hose on mine. ( years ago I had an issue with hose collapse at higher rpms ).The factory had a spring inside that kept it from happening.

Like you mentioned. When the car is moving the fans have little affect....unless the shroud won't allow air to bypass. This is why the newer factory fans have rubber flaps on the shroud anywhere air would build. It's pretty easy to do.

The top pick is a factory BMW fan. Bottom pic is one kind-of like yours and the flaps installed.

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Thank you everyone for taking the time to post your suggestions!
I just wanted to clarify that everything cooling system related is brand new as I replaced it all when I rebuilt the engine.

A lot of you are focused on my electric fan/shroud setup as being the issue, I mentioned earlier that I had the exact same issue with my stock clutch fan/shroud combo. I decided then to upgrade to to the LMR aluminum rad and add the fan/shroud combo. I have a Ryobi laser thermometer and seem to get erratic readings when I check various points, I have one at work that seems much better, I'm going to bring it home this week to compare.
The Holley coolant temp sensor is mounted as per the instructions in the metal tube from the front of the intake manifold that runs to the heater core, never mentioned anything in the Holley instructions of having to calibrate a temp sender.
Timing was checked and verified as per the Holley instructions with a timing light at 10 degrees.