Mystery Overheating
Thread Starter
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Senior User
Joined: Dec 2005
Posts: 126
Likes: 0
From: Bay Area, Calif
Mystery Overheating
89 B2, 4X4, 2.9 L, 5 speed, JBA headers & wire set, Jet power chip, Fram Air Hog, new radiator, water pump, new engine (less than 10000), thermostat, (in a nut shell--it was a complete body off rebuild--so new everything). I've been driving it since August of 2007 (one year) and only in the last 2 - 3 months it has been running a bit hot--just over the middle mark to the 3/4 mark. It has radiator fluid, no leaks that I can see, the level stays steady, no weird noises etc. Well, maybe when I turn on the AC--every now and again it makes a screach noise like when the belt is too lose, but I've tightened it. Any ideas? Is it posible it's only a short in the gauge? Things to check? Oh yeah, one last thing that just started about 2 weeks ago, when I first start it up, it idles a bit high--at about 1000 - 1100 RPM until it warms up and then drops to under 1000 RPMs. Related? Maybe?
Post Fiend
Joined: Jun 2002
Posts: 13,873
Likes: 3
From: Atlanta GA
> just over the middle mark to the 3/4 mark
Way too hot for one with a new radiator. As long as the shroud is there and this problem just started, I would look at the clutch fan being defective.
Way too hot for one with a new radiator. As long as the shroud is there and this problem just started, I would look at the clutch fan being defective.
Elder User
Joined: Dec 2007
Posts: 739
Likes: 1
Gotta agree with Rebocardo.
General question. Does it get a whisker hotter while driving through town? As in really starts going into that danger zone? (on a 2.9 it seems...anything over middle mark could almost be considered a danger zone) If it runs nice and cool running 60 down the highway, with the A/C on? And once you get it into town it starts climbing up a wee bit faster then we'd like to see? Normally points right at that fan clutch. When it starts to crap? It can't spin the fan fast enough to cool things down.
With a 2.9...let's see if we can get this figured out before the heads crack.
S-
General question. Does it get a whisker hotter while driving through town? As in really starts going into that danger zone? (on a 2.9 it seems...anything over middle mark could almost be considered a danger zone) If it runs nice and cool running 60 down the highway, with the A/C on? And once you get it into town it starts climbing up a wee bit faster then we'd like to see? Normally points right at that fan clutch. When it starts to crap? It can't spin the fan fast enough to cool things down.
With a 2.9...let's see if we can get this figured out before the heads crack.
S-
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 787
From: Simi Valley, CA
These 2.9's ran hot when they were new, several years old...all the time. It was a major complaint from customers back then.
Ford only lists one t/stat for these engines...197 degrees. What we used to do was drill a small hole in the t/stat...that seemed to help.
You can also use a cooler thermostat from a 302 (180 or 160), but you'll have to trim the edge so it will fit into the housing...that's another thing we used to do.
btw: Are you sure you installed the t/stat correctly? The element faces towards the engine.
Ford only lists one t/stat for these engines...197 degrees. What we used to do was drill a small hole in the t/stat...that seemed to help.
You can also use a cooler thermostat from a 302 (180 or 160), but you'll have to trim the edge so it will fit into the housing...that's another thing we used to do.
btw: Are you sure you installed the t/stat correctly? The element faces towards the engine.
Thread Starter
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Senior User
Joined: Dec 2005
Posts: 126
Likes: 0
From: Bay Area, Calif
Mystery Overheating
Well, I just replaced the fan clutch just so I could rule it out completely--and the problem is still there. It runs just below middle and during prolonged driving (20 minutes +), the needle goes to middle and as soon as I hit the AC, freeway or city--it runs to 3/4 of the way on the gauge. I'm getting pretty frustrated with it.
Thread Starter
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Senior User
Joined: Dec 2005
Posts: 126
Likes: 0
From: Bay Area, Calif
Overheating
These 2.9's ran hot when they were new, several years old...all the time. It was a major complaint from customers back then.
Ford only lists one t/stat for these engines...197 degrees. What we used to do was drill a small hole in the t/stat...that seemed to help.
You can also use a cooler thermostat from a 302 (180 or 160), but you'll have to trim the edge so it will fit into the housing...that's another thing we used to do.
btw: Are you sure you installed the t/stat correctly? The element faces towards the engine.
Ford only lists one t/stat for these engines...197 degrees. What we used to do was drill a small hole in the t/stat...that seemed to help.
You can also use a cooler thermostat from a 302 (180 or 160), but you'll have to trim the edge so it will fit into the housing...that's another thing we used to do.
btw: Are you sure you installed the t/stat correctly? The element faces towards the engine.
Thread Starter
|
Senior User
Joined: Dec 2005
Posts: 126
Likes: 0
From: Bay Area, Calif
overheating
Gotta agree with Rebocardo.
General question. Does it get a whisker hotter while driving through town? As in really starts going into that danger zone? (on a 2.9 it seems...anything over middle mark could almost be considered a danger zone) If it runs nice and cool running 60 down the highway, with the A/C on? And once you get it into town it starts climbing up a wee bit faster then we'd like to see? Normally points right at that fan clutch. When it starts to crap? It can't spin the fan fast enough to cool things down.
With a 2.9...let's see if we can get this figured out before the heads crack.
S-
General question. Does it get a whisker hotter while driving through town? As in really starts going into that danger zone? (on a 2.9 it seems...anything over middle mark could almost be considered a danger zone) If it runs nice and cool running 60 down the highway, with the A/C on? And once you get it into town it starts climbing up a wee bit faster then we'd like to see? Normally points right at that fan clutch. When it starts to crap? It can't spin the fan fast enough to cool things down.
With a 2.9...let's see if we can get this figured out before the heads crack.
S-
Trending Topics
Fleet Mechanic
Joined: Aug 2008
Posts: 1,446
Likes: 9
From: NE Iowa JD Country
The factory guages are also known to give false info.
OR do you have after market mechnical guages?
could be the temperature sending unit is on its way out.
If it Idles high then be looking into the temp sensor for the computer ,(not dash gauge). the TPS, O2 sensor, and or the AIC. Certainly look over the vacuum lines.
Does it Idle high always or just when warm or cold?
Have you tried to get the codes??
OR do you have after market mechnical guages?
could be the temperature sending unit is on its way out.
If it Idles high then be looking into the temp sensor for the computer ,(not dash gauge). the TPS, O2 sensor, and or the AIC. Certainly look over the vacuum lines.
Does it Idle high always or just when warm or cold?
Have you tried to get the codes??
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Post Fiend
Joined: Jun 2002
Posts: 13,873
Likes: 3
From: Atlanta GA
> Do you think the Jet Power Chip might be causing this
I doubt it because we would have seen people post about it in other forums a long time ago.
> I just replaced the fan clutch just so I could rule it out completely
Just for giggles, see if it spins freely while cold, then go heat it up, shut the engine off and see how it spins.
As long as the noise will not bother people, drop the cats at the Y pipe. Run it at high idle (2K) or drive it a short distance. A clogged cat. converter will surely overheat an engine. The way to tell is by reving it. If it is kind of slow with the cats and then without it pegs to 4K easy, the cats are clogged.
Exhaust pressure testers are kind of expensive to buy and I do not think they rent them.
After market cats are generally junk for most cars. If you can, a junkyard F-150 will work if you want to weld it in. Or buy a generic one with a 2.25 inlet.
I doubt it because we would have seen people post about it in other forums a long time ago.
> I just replaced the fan clutch just so I could rule it out completely
Just for giggles, see if it spins freely while cold, then go heat it up, shut the engine off and see how it spins.
As long as the noise will not bother people, drop the cats at the Y pipe. Run it at high idle (2K) or drive it a short distance. A clogged cat. converter will surely overheat an engine. The way to tell is by reving it. If it is kind of slow with the cats and then without it pegs to 4K easy, the cats are clogged.
Exhaust pressure testers are kind of expensive to buy and I do not think they rent them.
After market cats are generally junk for most cars. If you can, a junkyard F-150 will work if you want to weld it in. Or buy a generic one with a 2.25 inlet.
Thread Starter
|
Senior User
Joined: Dec 2005
Posts: 126
Likes: 0
From: Bay Area, Calif
gauges
The factory guages are also known to give false info.
OR do you have after market mechnical guages?
could be the temperature sending unit is on its way out.
If it Idles high then be looking into the temp sensor for the computer ,(not dash gauge). the TPS, O2 sensor, and or the AIC. Certainly look over the vacuum lines.
Does it Idle high always or just when warm or cold?
Have you tried to get the codes??
OR do you have after market mechnical guages?
could be the temperature sending unit is on its way out.
If it Idles high then be looking into the temp sensor for the computer ,(not dash gauge). the TPS, O2 sensor, and or the AIC. Certainly look over the vacuum lines.
Does it Idle high always or just when warm or cold?
Have you tried to get the codes??
Thread Starter
|
Senior User
Joined: Dec 2005
Posts: 126
Likes: 0
From: Bay Area, Calif
overheating / exhaust
> Do you think the Jet Power Chip might be causing this
I doubt it because we would have seen people post about it in other forums a long time ago.
> I just replaced the fan clutch just so I could rule it out completely
Just for giggles, see if it spins freely while cold, then go heat it up, shut the engine off and see how it spins.
As long as the noise will not bother people, drop the cats at the Y pipe. Run it at high idle (2K) or drive it a short distance. A clogged cat. converter will surely overheat an engine. The way to tell is by reving it. If it is kind of slow with the cats and then without it pegs to 4K easy, the cats are clogged.
Exhaust pressure testers are kind of expensive to buy and I do not think they rent them.
After market cats are generally junk for most cars. If you can, a junkyard F-150 will work if you want to weld it in. Or buy a generic one with a 2.25 inlet.
I doubt it because we would have seen people post about it in other forums a long time ago.
> I just replaced the fan clutch just so I could rule it out completely
Just for giggles, see if it spins freely while cold, then go heat it up, shut the engine off and see how it spins.
As long as the noise will not bother people, drop the cats at the Y pipe. Run it at high idle (2K) or drive it a short distance. A clogged cat. converter will surely overheat an engine. The way to tell is by reving it. If it is kind of slow with the cats and then without it pegs to 4K easy, the cats are clogged.
Exhaust pressure testers are kind of expensive to buy and I do not think they rent them.
After market cats are generally junk for most cars. If you can, a junkyard F-150 will work if you want to weld it in. Or buy a generic one with a 2.25 inlet.
Posting Guru
Joined: Jun 2008
Posts: 1,124
Likes: 0
From: Buckeye, AZ
There has been good advice here but first as I always do in a customer complaint of over heating is find a point and shoot temp gun or other means to make sure its getting hot. On some Ford gauges have seen voltage increase from alt curcuit move them up.
I noted your location but has it been getting cooler there recently to account for the higher start up idle?
I noted your location but has it been getting cooler there recently to account for the higher start up idle?
Thread Starter
|
Senior User
Joined: Dec 2005
Posts: 126
Likes: 0
From: Bay Area, Calif
Overheating
There has been good advice here but first as I always do in a customer complaint of over heating is find a point and shoot temp gun or other means to make sure its getting hot. On some Ford gauges have seen voltage increase from alt curcuit move them up.
I noted your location but has it been getting cooler there recently to account for the higher start up idle?
I noted your location but has it been getting cooler there recently to account for the higher start up idle?