Oil leak help

[Kidd7]

01 Ex 5.0 v8. Last oil change I used full synthetic for the first time, previously used a synthetic blend. Now I'm getting some drops on the driveway, I'm thinking the oil pan gasket. There is some oil on the exhaust pipe as it crosses under the oil pan, there is also some oil on the bell housing inspection plate, some looks to be dripping down, see pics. Is it the oil pan gasket or am I looking at a rear main seal, or something else? Thanks.

 

[imp]

01 Ex 5.0 v8. Last oil change I used full synthetic for the first time, previously used a synthetic blend. Now I'm getting some drops on the driveway, I'm thinking the oil pan gasket. There is some oil on the exhaust pipe as it crosses under the oil pan, there is also some oil on the bell housing inspection plate, some looks to be dripping down, see pics. Is it the oil pan gasket or am I looking at a rear main seal, or something else? Thanks.
View attachment 328256
View attachment 328257

Did you spill any oil topside? It takes a long time for a small spill to gradually find it's way down to where you are seeing it. Were the images taken only a short time after the change?

 

[rasouth]

I had a similar experience after an oil change. Mine was the oil filter not being tight enough and oil leaking from around filter gasket and being blown towards the back of the engine as I drove the car.

 

[Kidd7]

While it's quite possible I spilled some, I don't remember and also it's been a few weeks and we've taken a pretty significant road trip. I would think any spilled would have burned off on that road trip.

 

[Kidd7]

I had a similar experience after an oil change. Mine was the oil filter not being tight enough and oil leaking from around filter gasket and being blown towards the back of the engine as I drove the car.

I'll double check that. it'd be great If it is that simple of a fix.

 

[Kidd7]

No dice. I checked the oil filter this morning and it's nice and tight, doesn't seem to have oil around it either.
There was no puddling under the truck this morning. I have a pretty good slant at the top of my driveway, that's where she was parked last night. At the top of the drive the truck leans forward, whereas at the bottom of the drive she sits pretty flat, meaning the oil was resting toward the front of the pan last night and not level.
With the oil topped off, how high above the pan gasket would it sit?

 

[Kidd7]

I cleaned off the oil pan and tranny inspection plate pretty good this weekend and I'm keeping an eye on things to see if I can tell where the drip is coming from. It is intermittent, not always spots on the driveway.

 

[CDW6212R]

Cleaning the areas and watching them is the best way to find leaks. The pictures you posted do not look like oil, the wetness on the cat pipe looks like coolant. Look slow and hard at the top front of the engine, and work your way back and down. Coolant can end up at the back and bottom, coming from several places up front and top.

Are all of the fluids full? Pull the radiator cap if the overflow is down some, see if there is any air under the cap.

 

[Kidd7]

Don, you are correct it's coolant. The Ex sat all weekend and peed some. The radiator was low, I should have checked how low, but I just topped it off. I could not determine where it's peeing from. There is some puddling around the cam syncro and under the T-stat housing, I don't see any evidence of leaking around the T-stat, I'm thinking that is being blown back by the fan.
The water pump is wet around the bypass hose and the heater hose on the passenger side of the engine. The drip flows down the front of the engine and along the oil pan then dripping on the cat. I'm leaning toward the water pump leaking. Any further thoughts on that?
I've done enough reading about the water pump replacement to know I'll probably need to replace the timing cover, should I replace the timing chain & gears while I have access?

 

[CDW6212R]

I'd take a shot at more cleaning around the front, even though it's hell to reach anything with it all intact. I'd say take the time to replace the thermostat and the two bypass hoses. Look around there carefully and see if it may just be the hoses etc. The water pump should have two weep holes, one top and the other bottom, to allow coolant from the bearing area to show. Hopefully those are clear and dry. The timing cover and WP are both PITA to replace, so hope for neither, and the WP more than the timing cover.

My WP of my last 98 looked new when I bought it in 2019, but now I see a leak at the top weep hole. So I'm going to have to do both the WP and timing cover soon. Try hard to have a spare vehicle to drive for those jobs, and spend a day doing it if it goes well.

 

[Kidd7]

Got this weekend dedicated to finding and fixing this leak. I took the fan and shroud off for more room. The radiator was ~2-3 inches low, about the same level every time I've checked it. That's just above the shroud bolt; not far enough down to be level with the water pump and barely level with the T-stat. The overflow hose is not plugged. When I topped off the radiator I put the cap back on, which goes on very easily. Then squeezed the upper hose, it hisses but then pressurizes. Can't see any drippage. I replace the radiator cap, fits much tighter and now when I squeeze the upper hose no hiss.
I'm thinking as the pressure increased the coolant would spray out of the cap and get dispersed by the fan, mostly being burned off. Only after sitting a while would some eventually migrate down to dripping. Thoughts?
I'm going to replace the cam sync tonight cuz it keep screeming and maybe come back to this.

 

[CDW6212R]

The radiator cap is very important, but if it didn't hold pressure, the level wouldn't drop inches like you describe. So your cap might be failing, but it isn't likely the cause of the leak. I'd replace the cap with a quality new one anyway, good insurance and you want all of the air out(that's the job of the cap).

 

[Kidd7]

Got the cam sync replaced and have a new rad cap installed. I still have the fan & shroud off. I fired her to make sure timing is correct and let her come up to temp. I'll look for evidence of leaks tomorrow. when I shut her down the upper rad hose with firm and when I squeezed it pretty hard I could hear coolant going back into the overflow as opposed to the cap venting like before. That cap was in bad shape.

 

[Kidd7]

Upon inspection in the morning there was some puddling under the T-stat housing. Couldn't tell for sure, but I think it was the bypass hose. Replaced the bypass hose and the T-stat, when I started filling the coolant, it started dripping out of the T-stat housing. Had to tear it all down and RTV the mating area. Filled and burped, there appears to be no more leaking.

 

[1998Exp]

Upon inspection in the morning there was some puddling under the T-stat housing. Couldn't tell for sure, but I think it was the bypass hose. Replaced the bypass hose and the T-stat, when I started filling the coolant, it started dripping out of the T-stat housing. Had to tear it all down and RTV the mating area. Filled and burped, there appears to be no more leaking.

I would advise to rent (or buy) a tester and pressure-test. Until then you can't really see where it's leaking from. And, from a lot of experience - mostly of other members but also mine - when they reach 100K or so, virtually all these ancient design 5.0L V8s leak from the top right and left corner of the timing cover. That's where the coolant passages are and the gasket is very narrow around them. Unless it's major, K-seal usually does the trick.

 

[CDW6212R]

I have that kind of leak from my 98 cover. I think the last owner changed the water pump and likely loosened all of the bolts that are for the timing cover too(top two and bottom four). If the timing cover is loosened any amount, that will affect the gaskets. They seal great when new, but once disturbed, don't hold your breath.

K'seal doesn't solve big leaks, I tried two bottles of that last October. I did find a stop leak that works, but not permanently for mine. The Liquid Copper does a very good job of plugging bigger leaks. But it also will over time be worn away by heat cycling and coolant movement.

Always add some kind of additive for the water pump seals too. I like Water Weter, but there are several kinds. When the WP bearings begin to wear, the seals often will leak before the WP bearings are gone completely.

 

[crunchie_frog]

I would advise to rent (or buy) a tester and pressure-test. Until then you can't really see where it's leaking from. And, from a lot of experience - mostly of other members but also mine - when they reach 100K or so, virtually all these ancient design 5.0L V8s leak from the top right and left corner of the timing cover. That's where the coolant passages are and the gasket is very narrow around them. Unless it's major, K-seal usually does the trick.

This.

For OP, replacing this ~ $0.50 gasket will try your patience. If/when you do replace the gasket, you want to be sure the timing cover has not lost metal around the two upper ears on the timing cover or it may leak again. They have new covers for about ~ $60 or $70 on ebay. There is also the possibility of broken bolts, particularly those 4 around the two cooling ports at the top of the cover. Once you are in there and have the timing cover off, you will want to replace the timing chain and sprockets. There are numerous threads on this forum and some pretty good videos on youtube relative to this repair.