undetermined coolant leak 97 Explorer 5.0 v8

[stayford?]

97 ford explorer limited 2wd with 5.0 v8 engine 124000 miles all maint records kept up & done & used synthetic oil since new & I am only owner has been parked in heated garage all its life. 6 months ago water pump started leaking out of weep hole & shaft of pump had lots of play so I decided to replace it.I took fan & radiator out & removed water pump & while water pump was off used a garden hose with special homemade nozzel & flushed out the engine block by spraying water through the two big holes in front of engine. Flushed out repeatededly on both sides till absolutley clean while opening valve to heater core to also flush it out. Also flushed out radiator this same way in every direction untill absolutley clean. Then wash & clean every sealing surface & use rtv wher needed & install new water pump & replaced every rubber hose with new ones & used screw type hose clamps on all hoses & fill with pure water only at first to check for leaks. After running & insureing no leaks drain water out & put in high quality antifreeze mixture to 50/50. Now after 110 miles of use the vehicle has developed more coolant leaks than it has ever had & all comming from areas that you cannot see. The main leak is at rear of engine where nothing was done & only shows as a drip like it is comming from the rear main oil seal where ther is a visable drip hanging there & the metal inspection cover on the bell housing stays wet with coolant & the other leak is somewhere around front left side as the only thing visable is drips hanging on the front left side oil pan bolt heads. It is very frustrating to take your time & do a job as good & clean as you can & have a vehicle that does not leak a drop while it is at operating temperature & running & only leaks after it is parked for a day & continues to leak untill it is run again. No coolant has been added for 5 months & 350 miles of use so the leak is small but I do not want any leaks at all, as I am one that tries to keep it perfect & all original as much as i can. I cannot see the dye thing helping me because you cannot see the parts of the engine that the leaks are even with mirrows same thing with pressuring it up I suspect but thats what I will try when I get one that will fit the small radiator opening. My QUESTION is has any one had this problem & know what it takes to cure it? Trying to show pics: Cannot get an answer to How to post pictures in this forum.......

 

[Turdle]

Welcome to the forum.

I have several items for you to check

1- timing cover leak. Often induced with water pump change.
While parked on a level surface check for a drip on the harmonic balancer pulley toward the oil pan. ( the drip will travel from here to rear of pan)

2- small water pump bypass hose will often develop a split on he inside of the elbow. Especially if it is re used. You might see a slight spray from it if someone revs the warmed engine while you look closely.

3-I do not like the screw clamps as they will crack the plastic nipples, and do not provide a true circular seal unless tightened very tight. Use the proper spring clamps. They truly are less hassle in the long run.

For uploading pictures you will need to use a hosting site such as Photobucket and then copy the picture links into your post. Or, you can upload pictures directly to the forum with a paid Elite subscription.

 

[bobflood]

+1 on #1 above from Turdle. There are two places on the top corners of the timing cover where the walls - and hence the gaskets - are not very thick. Pulling off the water pump removes a number of bolts that go thru the timing cover into the block - and two of them are in the upper corners. Coolant then drips down the block and rearward along the oil pan to the back of the engine. It will get worse; eventually you are going to need to replace the timing cover gasket. Mine leaked for almost 4 years after the water pump replacement; kept getting worse slowly, finally failed and I had to go in and replace that timing cover gasket. Good luck.

 

[1998Exp]

+1 on that. Very likely to be the timing cover. However, there seems to be more to it than just a gasket failure. I did the timing cover job a couple years ago, and now see a small leak again, even though I put less than 5000 miles on the truck since then. Retorqued the bolts to no effect. My assumption is that when I took it off I did not notice that the cover was slightly warped, and now it got worse. This ancient design, with the lightweight timing cover supporting a heavy fan and being twisted by the serpentine belt tension was certainly asking for trouble; there is a reason that it was abandoned in newer engines. If you get to the point of taking the cover off, I would strongly recommend checking for flatness. Good luck!

+1 on #1 above from Turdle. There are two places on the top corners of the timing cover where the walls - and hence the gaskets - are not very thick. Pulling off the water pump removes a number of bolts that go thru the timing cover into the block - and two of them are in the upper corners. Coolant then drips down the block and rearward along the oil pan to the back of the engine. It will get worse; eventually you are going to need to replace the timing cover gasket. Mine leaked for almost 4 years after the water pump replacement; kept getting worse slowly, finally failed and I had to go in and replace that timing cover gasket. Good luck.

 

[soon2b351]

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