Hard to trace coolant leak + intake q

[TequilaSnrs087]

A while back I started noticing a coolant smell coming from my 1995 4.0 Sport. I popped the hood and saw very slight coolant seepage from the part of the radiator where the transmission cooler lines screw in. Nothing ever dripped to the ground, and it was such a tiny amount of coolant that I decided to leave it alone. A couple days ago I noticed that the coolant level was a little low in the resivoir. Not by much at all - just a little. I topped it off anyway so I could monitor the change in the level. Today I checked it and it was back to the same level it was at a couple days before. I also noticed coolant on the coil pack and on the connector for one of the fuel injectors. There was also a drop or two on that heater valve thing just to the left of the coil pack. I looked and could see that there was some coolant resting on the top of the lower intake manifold. I decided to go ahead and buy a gasket set. I checked it again later and everything was dry. No trace of coolant at all. This was after maybe 80 miles of driving. The resivoir level was the same when I checked again. So where could this coolant be coming from? How is it getting on top of the coil pack when that is above the intake? Could the heater valve be spashing coolant on to the engine? If it helps, the place that changed the oil last said they saw some coolant on the passenger side lower control arm. I assumed it had splashed out of the resivoir.

Also, if I do have to replace the intake gaskets, what should I expect? I have done some minor work before, but not intake manifold gaskets. Hayne's says you have to remove the valve covers to get the lower intake manifold off...is this true? If so, are there any tricks for getting that bracket that holds the coil pack unbolted from the exhaust manifold? Also, everything below the lower intake manifold is very dry with so signs of leaks, but I don't think there are coolant passages in the upper composite manifold that could leak coolant on to the lower intake manifold. Is this correct?

BTW - when I checked it this morning and saw the coolant, the heat had been on. When I checked it later and saw no coolant, the heat had been off...the HVAC was switched to blow in cool outside air. Sound like it might be related to that coolant valve?

 

[TequilaSnrs087]

I did some more looking, and I am leaning more towards that valve being the problem. I just don't see how coolant could be pushed that far up from its source, even with air movement under the hood. It would have to defy gravity. Plus, the valve rests right over the passenger side control arm, where coolant was spotted before. I doubt coolant from the intake manifold could travel that far. Also, there is a stain below the 2 halves of the valve. It looks like coolant, but was dry when I saw it.

Anyway, it looks like I will be replacing this valve as a first step. After a long drive I just could not find anymore coolant on the intake manifold. I couldn't get the valve to leak this time either, but if the intake manifold was leaking it surely would have gotten worse through the day and not better.

 

[96eb96]

I did some more looking, and I am leaning more towards that valve being the problem. I just don't see how coolant could be pushed that far up from its source, even with air movement under the hood. It would have to defy gravity. Plus, the valve rests right over the passenger side control arm, where coolant was spotted before. I doubt coolant from the intake manifold could travel that far. Also, there is a stain below the 2 halves of the valve. It looks like coolant, but was dry when I saw it.

Anyway, it looks like I will be replacing this valve as a first step. After a long drive I just could not find anymore coolant on the intake manifold. I couldn't get the valve to leak this time either, but if the intake manifold was leaking it surely would have gotten worse through the day and not better.

Coolant has a way of getting around. Buy a motorcraft one, the after market ones are crap and leak in a year. Rockauto has it for ~$15 and you can find a discount code online. It is actually cheaper than the aftermarket unit!!!

 

[TequilaSnrs087]

I know a guy at a Ford dealer who can get me a hefty discount on parts, so I'll go to him on Monday.

Coolant does have a way of getting around, but with coolant making it all the way down to the passenger side lower control arm, it has the heater control valve's fingerprints all over it.

 

[00XLS]

Where is this located on a OHV? I have a leak that I can't trace down to save me, no smell ect. Coolant just disappears...

 

[TequilaSnrs087]

In my truck the heater control valve is on the left (passenger) side of the engine compartment. IIRC, it has 3 or 4 hoses coming and going from it and a vaccum line. Digging through the forums, it appears to be a common issue. I hope replacing it will fix all of my coolant issues. It seems to be the culprit judging from the stain on it and the fact that all of the leaking coolant has been spotted around it. My coolant loss is very minimal at this point, but I want to solve this issue before it becomes a hassle.

 

[jakeamondo]

coolant leak

I have a '95 4.0 in my explorer app 100,000 miles. I traced the coolant leak to the rear of the engine, passenger side. It was spraying all over and bouncing off the firewall. It ended up being the the lower intake manifold gasket at the rear passenger side. The gasket at the water port was brittle and ripped. Be careful with the haynes manual regarding the lower intake gasket. I used the ford gasket F5TZ-9439-A, and was amazed how well it fit. You must use guide posts at the drivers side rear and passenger front to align the gasket and lower intake. Haynes recommends using RTV sealant around the water ports and end seals, as well as the the four corners near the end seals. Ford only indicates RTV at the four corners. I did a little research and found several vacumn leaks, and coolant leaks occurred after using the RTV sealant at the extra locations. If you look at the permatex site, you will see that not all RTV sealants are compatable with rubber gaskets, and they make no recommendations for water port applications. The four corners above and below the gasket require RTV that is oil resistant. Not
many RTV sealants are both oil and pressurized coolant safe. Ford recommends specific coolant see attached

Engine Coolant - Propylene Glycol Recommendations
Article No.
01-23-6

11/26/01

^ ENGINE COOLANT - PROPYLENE GLYCOL - FORD
MOTOR COMPANY POSITION ON ENGINE
COOLANTS MADE FROM PROPYLENE GLYCOL

^ ENGINE COOLANT - PROPYLENE
GLYCOL-BASED - FORD MOTOR COMPANY
POSITION ON PROPYLENE GLYCOL-BASED
ENGINE COOLANTS

FORD:
1989-1993 FESTIVA
1989-1994 TEMPO
1989-1997 PROBE, THUNDERBIRD
1989-2002 CROWN VICTORIA, ESCORT, MUSTANG, TAURUS
1994-1997 ASPIRE
1995-2000 CONTOUR
2000-2002 FOCUS
2002 THUNDERBIRD
1989-1990 BRONCO II
1989-1996 BRONCO
1989-1997 AEROSTAR, F SUPER DUTY
1989-2002 ECONOLINE, F-150, RANGER
1991-2002 EXPLORER
1995-2002 WINDSTAR
1997-2002 EXPEDITION
1999-2002 SUPER DUTY F SERIES
2000-2002 EXCURSION
2001-2002 ESCAPE, EXPLORER SPORT TRAC, EXPLORER SPORT
2000-2002 F-650, F-750

LINCOLN:
1989-1992 MARK VII
1989-2002 CONTINENTAL, TOWN CAR
1993-1998 MARK VIII
2000-2002 LS
1998-2002 NAVIGATOR
2002 BLACKWOOD

MERCURY:
1989-1994 TOPAZ
1989-1997 COUGAR
1989-2002 GRAND MARQUIS, SABLE
1991-1994 CAPRI
1991-1999 TRACER
1995-2000 MYSTIQUE
1999-2002 COUGAR
1993-2002 VILLAGER
1997-2002 MOUNTAINEER

MERKUR:
1989 SCORPIO, XR4TI

This article is being republished in its entirety to update the model year coverage.

ISSUE
This TSB article describes Ford Motor Company's position on the use of propylene glycol-based engine coolants.

ACTION
Ford Motor Company does not recommend nor endorse the use of engine coolants made with propylene glycol in Ford vehicles. Ford Motor Company currently recommends the use of ethylene glycol-based engine coolants.

Published information suggests that engine coolants made with propylene glycol may provide engine cooling performance equivalent to engine coolants made with ethylene glycol. However, different brands of engine coolant provide varying corrosion protection for the cooling system. Ford does not have performance data for the multitude of engine coolants available in the aftermarket and therefore cannot recommend the use of any coolant except those sold by Ford Customer Service Division. Consult the vehicle's Owner's Guide to determine the appropriate Ford Customer Service Division coolant for the vehicle.

Furthermore, claims of toxicological and environmental advantages of propylene glycol over ethylene glycol may be misleading. When significant new information is developed, Ford will review this policy.

Ford Motor Company specifications recommend that vehicles be maintained using certain ethylene glycol-based engine coolants. Those specifications do not refer to engine coolants made with propylene glycol. Although the Ford New Vehicle Limited Warranty is not automatically voided upon the use of a coolant made with propylene glycol, if such use results in damage to the vehicle or its components, the cost of repairing the damage would not be covered by the Ford New Vehicle Limited Warranty.

OTHER APPLICABLE ARTICLES: NONE
SUPERSEDES: 96-16-4
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES

 

[TequilaSnrs087]

Thanks for the info.

I replaced the heater valve today and I am not getting anymore coolant on the coil pack. Everything is nice and dry now.

 

[00XLS]

How hard to replace it ?

 

[TequilaSnrs087]

Pretty easy. The most difficult part was getting the factory clamps off. Just remove the four hoses and the vaccum line, put new clamps on the hoses, then reassemble. You may want to put a drain pan below the valve, but I didn't really drop much on the ground. Afterwards I bled the cooling system, though it didn't seem needed in my case.

 

[TequilaSnrs087]

I'm digging this up because apparently my coolant issues are not over with.

The Explorer was fine for a couple days after I replaced the valve. Then I saw coolant again after driving to work. Same place as before. I gave up and took it to Firestone for a pressure test today to verify for certain the source of the leak. They could not get the truck to reproduce the leak at all. So I'm back to square one. It SEEMS like the intake manifold, but I want to be sure.

The problem could be temperature related. It seems like driving in temps below freezing are more likely to result in a coolant leak.

 

[Pollarican]

I feel your pain, those coolant leaks are a PITA to track down sometimes. My lower rad hose would only leak when the motor was running and the system built pressure; you might want to give it a look with the hood popped and engine running if you haven't already.

This might help you out a bit if you think it is an intake manifold gasket: http://www.explorerforum.com/Singleton/web/pages/coolant3.html

 

[jakeamondo]

Coolant leak

Always find the source first, The rear water ports are directly behind the rear lower intake bolts and the front ports are directly in front of the front bolts. The rear ports are cast into the lower intake manifold and are dead ends, air can get trapped in that area. In cold weather your thermostat may open slower, resulting in a pressure build up at the rear ports. Any trapped air will compress. Normal coolant system pressure occurs when the glycol is operating temperature. I would try refilling the system and getting the air out,the leak may only occur when the system is full. With a cold engine, open the radiator cap and add 50/50 mix, fill the resevoir to the low mark. Run the engine with the radiator cap off until the thermostat opens, the upper hose will be hot when the stat opens. Turn the car off and refill the radiator to the top. Sqeeze the upper hose to remove any air. fill if necessary. replace cap, run car again until it reaches operating temp. Now with a full system check for leaks. When replacing lost coolant should also have the heat at max temp. Get a good mirror to check for leaks. The outter mating surface of the rear water jacket gasket is flush with the block and the edge of the lower manifold, sometimes you can see where it blew out.

 

[jakeamondo]

The haynes manual is correct the valve covers actually bolt to the upper intake on the inside and to the heads on the lower side. The egr bolt and the coil pack to manifold need a little work to loosen. spray with penetrating oil, tap the bolt head. If someone used loctite on the threads, you have to apply heat to loosen. Caution penetrating oil is flammable. You will need to replace the upper intake gasket as well as the valve cover gaskets. While your down there you should do the fuel rail to lower intake gasket and the fuel injector O Rings. I sent my injectors out for cleaning etc. One was bad even though the Resistance (Ohms) was correct.

 

[makena]

For what it's worth

I have a 96 XLT with a coolant leak problem. Probably a cup or so leaks in the drip pan on the garage floor but no leak is apparent when the car is parked cold, nor when it is hot and watched. The leak always seems to happen overnight.

A few years ago I had a leaking heater control valve. It was replaced. 18 months later it was leaking again, and was replaced. Now, 12 months later I have a leak again. I believe it only leaks when the engine is cooling down. That is, when hot, no leak. When cold and no pressure, no leak. But at some point when cooling down overnight, it leaks from the seam on the HCV.

I placed some paper towels under key hose connections which were all dry when parking the car hot and let them stay overnight. Sure enough, next morning the paper towel under the HCV was stained and wet. It had caught that day's leak.

Now...I bought yet another HCV. I could use someone's help here. I think perhaps the mechanic who did the original replacement connected it wrong and that might be why mine keep failing. There are 2 ports facing back to the firewall, which go to the heater core, and I'm guessing their connections are interchangeable since the core has no direction. On the 2 ports facing forward toward the engine, the lower one has an arrow indicating flow INTO it, and the upper one has no arrow.

I notice that the hoses connected to the front ports don't seem right. The hose which goes over the TOP and into what appears to be the top of the engine, next to where the upper radiator hose connects to the engine, is connected to the upper port, not to the lower one with the arrow IN marked on it. The hose connected to the upper port with the arrow IN, is routed down beside the engine and turns upward to connect to what may be a port on the side of the water pump. I think this is backwards, and the mechanic made the mistake when he installed it.

Can someone look at theirs and tell me? The hose that comes UP off the engine goes to which port on the HCV? And the hose that goes down from below the area to the left of the engine fan, then loops back up beside the engine, goes to which port? Any help would be appreciated, a photo would be even better! I'll be happy to take one too.

OK next, I just noticed the small hose that goes from the radiator cap, along the top of the radiator, to the resevoir, is attached to the resevoir with no clamp. It is not a pressure hose, so that may be as intended. But I felt down there under the resevoir and it seems wet. I suppose adding a small clamp would not hurt anything.

Any help appreciated. BTW, I have had nothing but leaks with this car. Oil, transmission fluid, coolant, you name it. Front and rear engine seals replaced to stop massive oil leaks, and we're still leaking more. Getting time for a new car I guess but at only 90K miles seems I should be able to keep going.

PS, anyone know if I hook the two ports on the HCV backwards what the effect might be? If I can't get a good answer I'm just thinking of swapping them to see what happens.

 

[96eb96]

I have a 96 XLT with a coolant leak problem. Probably a cup or so leaks in the drip pan on the garage floor but no leak is apparent when the car is parked cold, nor when it is hot and watched. The leak always seems to happen overnight.

A few years ago I had a leaking heater control valve. It was replaced. 18 months later it was leaking again, and was replaced. Now, 12 months later I have a leak again. I believe it only leaks when the engine is cooling down. That is, when hot, no leak. When cold and no pressure, no leak. But at some point when cooling down overnight, it leaks from the seam on the HCV.
.

What brand HCV did you buy? This usually happens with the aftermarket non-motorcraft product.

 

[makena]

Thanks for the reply. The auto parts store did not have Motorcraft, it was "Factory Air" part #74809. I notice that part number is sold under other names too.

I guess I could order Motorcraft and have it shipped.

Any idea though on the hose connections? I wish I could see some photos of the HCV up close as it came OEM from the factory.

 

[makena]

FYI, I installed the aftermarket one 2 days ago. I swapped the hoses as I mentioned above, because I confirmed in a few different places that the hose connected to the ARROW-IN port on the valve (fluid flows into the valve) should be the one coming from the engine block, not the one going to the water pump.

Everything looked great the first day.

Today I noticed a spot, just a few drops, of coolant on the drip pan under the car after being parked overnight. Sure enough, the brand new valve is leaking. The leak seems to be in the same place that the previous one leaked, right around the "cap" that seems like it is molded or glued on nearest the IN port. So looks like I'll be changing this again. This will be my 5th Heater Control Valve on this car. I definitely will be doing the Ford Motorcraft one this time, ordering it by mail.

 

[jakeamondo]

Coolant leak/heater valve

The arrow, i believe is the valve position. the top hose goes to the water pump, the bottom to the intake manifold. The top hose coming out of the valve back goes to the left side of heater core. There is a bypass built into the valve, so that when its closed, the water will still circulate.

 

[ngrover]

The rear ports are cast into the lower intake manifold and are dead ends, air can get trapped in that area.

jakeamondo, you have some seriously helpful information for me here. I have a couple comments / questions. First, I just went and got my new lower intake gasket. I asked for the same part number as you ( F5TZ-9439-A ) and was told they didn't have that in their system. The interesting thing was, he sold me a gasket with part number F7TZ-9439-AA which looks exactly like images of the one you have EXCEPT that the rubber coating on the rear ports is filled in (blocking off the rear ports all together). Perhaps this is an updated version that solves the trapped air issue you were talking about.

Now for my question. After reading your post regarding RTV I was un-clear as to where to apply it. I bought some RTV that is coolant, gas, and oil safe ($18 bottle). Where do you suggest I apply it? I assume that wherever I apply it I must do it to both sides. Thanks for your help. There doesn't seem to be a wealth of information about this issue. My gasket blew out a chunk and coolant spews everywhere.