Mystery leak *pic*

[Buggyman]

Just replaced the head gaskets on this 2000 3.0, everything ran fine and noticed no leaks while running distilled water through the cooling system, I then added some Zerex flush solution and let it circulate for about 30 minutes then drained and flushed about 5 times with distilled water trying to get all the crud out. I noticed during one of my flushes this small leak on the block, I cannot tell where its coming from, it appears to be behind the water pump, below where the head meets with the block and looks like it originates where one of the water pump bolts goes into the timing chain cover. I tried to tighten that bolt and the surrounding ones down slightly more but it still slowly leaks. No leaks are visible when the truck is started, I have checked both while the motor is cold and hot. Any ideas? I do not feel like its the head gasket because its dry around the head gasket, I don't think its the water pump because its behind it, only thing I am not sure of is the lower intake gasket. I torqued everything to spec, used RTV where required and double checked my torque before putting it back together. Also, I had the water pump out for part of the head gasket job and I replaced the water pump gasket, used RTV sealant on both sides of the gasket and used a little sealant on the threads of the long bolts, I have been keeping an eye on the oil condition and so far no signs of H20.

Thanks for any ideas, sorry about the bad picture quality, I had the pictures rotated on the computer to show up/down but the site flipped them back, hopefully it gives the idea of where its leaking.

Philip

 

[adsm08]

Water pump and front cover gaskets are common leak points on the 3.0.

The inlet and outlet passages for the water pump pass through the front cover, and so that gasket can fail and cause an external leak. Just get a timing cover set and replace the gaskets. Your flush probably knocked loose some crap that was blocking a minor leak.

 

[evanesce69]

I agree... if you replaced the head gaskets because they were blown, then you probably overheated too. The expansion/contraction of the aluminum timing cover weaken the gasket, then when you used the flush to remove the "gunk" you also removed the material sealing that leak. It's not fun replacing the timing cover/water pump gaskets with the motor in the vehicle. The front cover is integrated into the oil pan gasket sealing area. The front pan gasket, timing chain cover gasket and crank seal will need to be replaced. It's a good idea to replace the water pump at this time too. The impellers on these water pumps like to corrode away which leads to reduced coolant flow and cooling efficiency. Judging by the gunk, and color of the area around the leak there was quite a bit of rust inside cooling system which is a good indicator that the pump impeller is compromised. The photo also tells me that its not a new leak... It has leaked there before in the past... The dry rusty area in contrast to the black oily residue is the giveaway.

Another thought, like you mentioned before, could be the intake water passages leaking. I've noticed in the past that if the intake isn't aligned properly and torqued in the correct sequence that the water passages can leak, even after sealant is applied. It is also best to be patient, don't rush things. Take time and allow the sealant to fully cure before adding coolant and operating the engine, otherwise it can be pushed out of place when the engine warms up and pressure builds within the cooling system.

 

[Buggyman]

Thanks for the replies,

I am pretty sure its leaking around the timing chain cover. Is it possible to remove it and reinstall it without removing the oil pan? Its a 4x4 and I read that you have to pull the motor to access the oil pan. Also noticed another leak that I traced back to the heater core, looks like I will be taking the dash apart after this, I will probably bypass it for now. This truck has turned into a project well beyond what I was expecting or hoping to spend but I feel like I have too much invested to not keep fixing things. Thanks for all the help, this forum has been tremendously helpful!

 

[rustywrench]

Thanks for the replies,

I am pretty sure its leaking around the timing chain cover. Is it possible to remove it and reinstall it without removing the oil pan? Its a 4x4 and I read that you have to pull the motor to access the oil pan. Also noticed another leak that I traced back to the heater core, looks like I will be taking the dash apart after this, I will probably bypass it for now. This truck has turned into a project well beyond what I was expecting or hoping to spend but I feel like I have too much invested to not keep fixing things. Thanks for all the help, this forum has been tremendously helpful!

Keep an eye on the radiator too.......Have had this issue on a '91 Ranger 3.0 and a '99 Ranger 3.0........after flushing a couple of days later the radiator goes to leaking at the seams between the tank and core........

 

[delaware74b]

Buggyman - I changed the front cover gasket and water pump on my '04 3.0. I see you have 220K on your engine. Change the timing set while you're in there. It's about $40 for the 3-piece set and it's only 1 more bolt to change it. Pull the radiator for room and the pulley section unbolts from the crank damper. Oil pan did not have to be pulled on my engine. I was able to reuse the existing oil pan gasket and used the gray rtv to seal the bolts and gaskets. You will have to change the oil and filter due to coolant getting into the oil pan. I changed all this on Black Friday after seeing another puddle under my truck......