• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

2.3L ('83-'97) What is the coolant line feeding the intake manifold for, cooling or heating??


corerftech

Well-Known Member
Joined
Apr 22, 2021
Messages
308
City
Memphis, TN
Vehicle Year
1987
Transmission
Automatic
Usually (unless I have been completely mistaken my entire life) the coolant lines that feed or run into or through an intake manifold are for heating the manifold for fuel vaporization. To keep it from puddling or otherwise assist in fuel temperature control.
With the 2.3L engine, is this true or is it for cooling purposes???

Mine is blocked off. The pipe has been removed and the spigot on bottom of lower manifold is plugged. I am assuming if my understanding is correct, the only defect I should face is potentially MPG, cold condition operation, warm up, etc. Nothing to cause a failure of the engine or its components.

I have been chasing a ghost miss for over a month on Frankentruck. Anybody having read anything here in the last month knows of Frankentruck and it’s exhaustive electrical and assembly issues.

I last posted of an egr tube leak, successfully repaired with JB weld. This altered the way the truck ran for the better again. Changed plug wires but after a couple of days of testing I found the tach bouncing now consistently and it was still popping at start up.
Yesterday I replaced thr 8th spark plug wire, #4 on secondary coil as prior light/time precluded me doing so. I tried to chase a factory found splice as a last resort to find the source of tach bounce. Prior a new ICM (2 months) had resolved the tach bounce but it did come back.

Tearing the loom apart I decided to start the truck with the secondary coil disconnected. The truck ran on two cylinders. I freaked out thinking the primary coil, a replacement, had failed. I dropped in a motorcraft replacement from a 302
Dangling on top of engine and attempted to start, massive backfire.

Quickly I realized that for the last 45 days, from when my final assembly of the car took place, I miss wired the primary coil and properly wired the secondary. The start up pop was a dead misfire from a swap of cyl 4 and 2. The thing is other than the engine acting like is was hunting for timing at startup, the car ran well on the secondary coil but not perfect.
The bucking at 17-2000 rpm was indeed the spark plug wiring error.
Now the truck idles like a sewing machine, 5th gear hill climbs from 1100 rpm don’t even lug- it just slowly and smoothly makes it way up. Every start sound alike my wife’s expedition, perfect.

The tach still bounces and this is the crux of the coolant line question.

The Standard brand ICM is about 2 months old or so. It has low hours, roughly 650 miles on it. I have gotten code 18/88 for SPOUT and IDM problems AGAIN.

It’s intermittent and seems to come to life when the engine was warm (never hot) and my concern is that even with replacing the coils and ensuring all harness is perfect, having heat sink greased and properly cleaned and torqued the 3 mounting bolts—— that I have somehow overheated the ICM by NOT having the coolant line attached (last owner disabled and parts are missing).

Or as I have read, ICMs even new are hit and miss—— it has always had a tach bounce, it’s intermittent and comes and goes but the last 36 hours it seems here to stay. The CEL is new to the last 36 hours and is a monkey that was off may back for 60 days.

I have ordered a new ICM under warranty replacement, I’ll replace and see if a new one behaves different. Cost is $10, my one shot replacement.
Need to know about the cooling line and it’s reason to exist.
Manifold is warm to touch after hard runs and not cold like many I have tested but not more than maybe 140 degrees- certainly comfortable to keep hand on.

What is concerning was yesterday it threw an 18/54/88 and the 54 is the IAT HIGH out of range. That’s what caused the ground splice search as they are grounded at same place in harness. High resistance ground for IAT would create a 54 and potentially an IDM/SPOUT code. The grounds are perfect so did the air temp rise so high that it coded??? I have the heat riser installed but haven’t tested the vacuum control over it. Could it not closing off warm air be raising the air and manifold temp to critical? Or did running the car for 600 miles with two coil towers backwards cause the issue??

Or just a low budget $88.00 Chinese ICM that you buy two to get one that works?? Standard T series from RA.

I appreciate any feedback on the matter

I am embarrassed about the recoil miss wire. It’s funny so laugh please on my behalf/——- but I feel utterly stupid. And I never thought to verify as the secondary coil would kick in at 400 rpm and cover my mistake!!!

Stupid dual coil system———— made a stupid mistake by me-almost invisible.

Mike
 
Last edited:
Your engine is fuel injected correct? So your intake manifold has no fuel in it. Instead of a "wet manifold" like a carb would have, you have a "dry manifold" with only air in the intake. On those types, the coolant is usually used to keep the EGR area cooled off. And they do sometimes route it threw the throttle body area, frost can build up from the refrigeration affect from the throttle being partially closed and humid air passing through.
 
The 3.0l Vulcan engines used heater hose lines to throttle body to prevent icing in that location
Icing will cause running issue in colder temps, under 45degF usually, fast air flow can get quite a bit cooler in the intake
Any moisture in the outside air can freeze on contact to colder metal
Ice particles are not great for air/fuel mix, lol, and icing can also cause throttle to stick

PCV Valves also use heaters as well, to keep oil vapor warmer so valve doesn't stick
 
I remember my ‘88 2.3 having a coolant line on the intake but the 94 I drive now doesnt, maybe it should have but has been disconnected, my heater hoses now just go from water pump/thermostat to heater core, I’ll have to go out to the garage & see if there’s a fitting on the intake manifold, Ive had this engine apart before to replace a head & head gasket but dont recall seeing one, been a few years though.
 
My ‘94 2.3 has no coolant lines in any intake parts. I do have an intake air heater hose from the intake tube to the exhaust manifold shroud. Could that be an either/or type thing?

Edit: dual plug, fuel injected
 
Last edited:
The carb version and single spark plug head intakes for the 2.3l had coolant circulation, dual plug heads were different
 
The carb version and single spark plug head intakes for the 2.3l had coolant circulation, dual plug heads were different
Yep, no fittings on my 94. (dual plug head)
 
Injected- yes- didn’t think about the concept of a dry manifold, thanks for making the distinction-

yep, so it seems all replies are “not critical”, then I won’t put blame on lack of the coolant line to manifold as cause of ICM failure (if it failed at all).
Kind of sick of the ICM to be honest.
 
Injected- yes- didn’t think about the concept of a dry manifold, thanks for making the distinction-

yep, so it seems all replies are “not critical”, then I won’t put blame on lack of the coolant line to manifold as cause of ICM failure (if it failed at all).
Kind of sick of the ICM to be honest.

I remember reading about this quite a bit. I don’t know why as I’ve never owned a car with a “cooled” manifold. It could have been a rabbit hole I went down when I was reading about my intake air heater. To put it mildly, it was a hotly debated topic, ie: is it cooling or heating, does carbureted vs injected matter, does it really help anything, does climate affect its necessity, etc.

I don’t recall a definitive answer, but the argument I found most compelling was that it’s heating the manifold, only needed for carbureted engines (higher vacuum in venturi), it’s only a problem when it’s cold (don’t know how cold… ice issue? Vaporizing issue?), and if there’s a leak you can just bypass it… perhaps sacrificing some peace of mind.
 
The 3.0l Vulcan engines used heater hose lines to throttle body to prevent icing in that location
Icing will cause running issue in colder temps, under 45degF usually, fast air flow can get quite a bit cooler in the intake
Any moisture in the outside air can freeze on contact to colder metal
Ice particles are not great for air/fuel mix, lol, and icing can also cause throttle to stick

PCV Valves also use heaters as well, to keep oil vapor warmer so valve doesn't stick

Mine have been removed and blocked off for 22 years. I drive it in single digit weather every year. Will be the next three days. Never had a problem with them being removed. Never any evidence of freezing. The only Ford I have with a heated PCV valve is my 2007 Mustang. My 98 Ranger and 04 Lightning just have a bare plain PCV valve. And they're both still the factory stock parts, never been replaced.
 
I remember reading about this quite a bit. I don’t know why as I’ve never owned a car with a “cooled” manifold. It could have been a rabbit hole I went down when I was reading about my intake air heater. To put it mildly, it was a hotly debated topic, ie: is it cooling or heating, does carbureted vs injected matter, does it really help anything, does climate affect its necessity, etc.

I don’t recall a definitive answer, but the argument I found most compelling was that it’s heating the manifold, only needed for carbureted engines (higher vacuum in venturi), it’s only a problem when it’s cold (don’t know how cold… ice issue? Vaporizing issue?), and if there’s a leak you can just bypass it… perhaps sacrificing some peace of mind.
Engines do not burn liquid fuel very well. It needs to be atomized into a mist to be properly distributed and burned. A carb or throttle body injection fuel system does fairly well in atomizing the fuel initially, but once the fuel mist hits a large cold intake manifold it instantly turns back into fuel droplets. The fuel droplets roll around in the bottom of the intake. Sometimes they all run into a certain cylinder and then cylinder burns rich, while the other ones are now only getting air, and they miss-fire. This is why engines run so rough when they are cold. All this added heat, richer air to fuel ratio, higher idle speeds, are all bandaids added to help the engine run better till it warms up and the fuel stays atomized better.
 
Actually its gasoline vapor thats needed, and cylinders tend to vaporize it pretty well once warmed up, but Choke is need to get enough vapor for cold starts

But yes inside of the intakes(runners) would get coated with gasoline using a carb, with fuel injection, at the intake valves, just the head ports and back of valve gets coated, carb conversion injection still gets the coating in the runners

Direct injection is best, all the fuel gets into the cylinder, no waste
 
Direct injection is best, all the fuel gets into the cylinder, no waste

I wonder what the latest injection system is? I was reading a article the other day about when they came out with gasoline direct injection, they had terrible intake coking problems. In other words, all that black sticky carbon on our throttle bodies were clogging the complete intake system and the valves on a direct injection system. They explained that some of the OEMs (I think Ford was one of them) actually went to a hybrid system with a dual injection system, using injectors behind the valves like the older system to keep them clean, and also using direct injection injectors for the fine fueling adjustments. I haven't read lately if they have come up with anything else, but apparently the coking problem was a serious one for the direct injection engines.
 
I wonder what the latest injection system is? I was reading a article the other day about when they came out with gasoline direct injection, they had terrible intake coking problems. In other words, all that black sticky carbon on our throttle bodies were clogging the complete intake system and the valves on a direct injection system. They explained that some of the OEMs (I think Ford was one of them) actually went to a hybrid system with a dual injection system, using injectors behind the valves like the older system to keep them clean, and also using direct injection injectors for the fine fueling adjustments. I haven't read lately if they have come up with anything else, but apparently the coking problem was a serious one for the direct injection engines.
You’re supposed to only use top tier gas in DI engines. Walnut blasting the valves is a regular maintenance item at 100k or so if power is decreasing. I’ve seen a couple vehicles advertised as having both. I want to say the new Tundra?
 
I wonder what the latest injection system is? I was reading a article the other day about when they came out with gasoline direct injection, they had terrible intake coking problems. In other words, all that black sticky carbon on our throttle bodies were clogging the complete intake system and the valves on a direct injection system. They explained that some of the OEMs (I think Ford was one of them) actually went to a hybrid system with a dual injection system, using injectors behind the valves like the older system to keep them clean, and also using direct injection injectors for the fine fueling adjustments. I haven't read lately if they have come up with anything else, but apparently the coking problem was a serious one for the direct injection engines.

Ford has converted some of the DI engines to both DI and Port injection for the reasons you state. Not all of them have it yet but I couldn't tell you which ones don't have it yet other than the 2.3 Ecoboost.
 

Sponsored Ad


Sponsored Ad

TRS Events

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Ranger Adventure Video

TRS Merchandise

Follow TRS On Instagram

TRS Sponsors


Sponsored Ad


Sponsored Ad


Amazon Deals

Sponsored Ad

Back
Top