Coolant Leak 4L OHV

[99 XL]

Sounds simple right? First noticed steam from under hood, smelled sweet like coolant. Hoses, heater core, frost plugs/block heater all good. Pressure test shows intake gasket at right rear corner leaking onto firewall, then dripping down onto block and exhaust pipe. According to the garage this will be their third one on the 4L OHV in 2 months! Parts delivery is backlogged. Is there an upgraded gasket on the way? Is this a common problem w/ the OHV?

 

[410Fortune]

are you SURE they did a pressure test?
Could be pulling your chain...

the most common place for a coolant leak on a truck like yours is from the heater control valve, it is mounted on the passenger side right at the firewall. This plastic vavle turns coolant flow to the heater core on and off, it is real common for them to leak when they get older. It is a $20 part and easily replaced with some hose clamps.
If it is leaking it can drip down the firewall.

It is NOT common for a 99 OHV to have head gasket problems UNLESS the truck was overheated.

Dont let them rip you off, if you even suspect they are BS'ing you look into it deeper before writing a check...

 

[CodePoet]

If you'd like to verify what they said fairly easily (possibly save some money if they are pulling your chain like 410 said) is goto an autoparts store and get a dye kit. I'd talked about them before...no one listens to me, but what it is is a dye that put in the coolant, you drive around for awhile just so the leak occurs, then you use a blacklight (sometimes privided in the kit) and shine it around the engine bay...the place where the coolant is leaking from will show up like a sore thumb, you'll deffinitly know where it's leaking from. Just an option if you wanted to check for yourself.

Good Luck
CP

 

[lonestar]

I have been losing antifreeze also. It was about a gallon low last week and I would start to heat up at a light. Now I have been keeping an eye on it and my overflow resevior goes empty in about a week from the cold full level. I can't tell where it is going. NO white smoke out the exhaust, no foam in the oil and I don't see any water anywhere. I guess I will let it idle in the drive for awhile and see if I can find anything.

 

[410Fortune]

Look at the underside of the waterpump for evidence of leakage

Look at the passenger side floor, is the carpet wet, is there any signs of leaking up there under the glove box?

Just because it does not leave a puddle doesnt mean its a head gasket., it can be evaporating on the exhaust, or just leaking somewhere you wouldnt expect, like the radiator cap.

The DYE method is your best bet however, its a sure fire way to QUICKLY find a leak.

 

[jhoch]

I'd like to kinda add to this topic,

you'd said that Heater control valve leaks are common on 4L's?

I've replaced mine 3 times now, and I get home tonight, and it is dripping once again like there is no tomorrow.

Is this common? is there anyway to stop this?

they are only $20 parts, but they should do a little better than that right?

 

[lonestar]

Just bypass the valve, use two straight hose fittings, or replace with a single hose.

It either only opens when HEAT is on or shuts when AC MAX is on to cut flow off to the heater core. I added a valve to my 1st gen after seeing one on a Ranger to help my AC, I didn't notice any difference. As long as your BLEND DOOR works it shouldn't matter if the heater core gets warm while running AC.