Hey guys my 302 in the RX7 has been leaking coolant. Its now got about 4k miles on it and had no issues before 4 weeks ago when I took it out playing in the snow only to find steam coming up after a few slides in a parking lot. I found that coolant was spraying out the side of the water pump onto the inner fender. I took the water pump and got new gaskets but today it was leaking again. It is puddling up in the two little spots on top of the timing cover. This time I think its the timing cover. Is there a common issue of this on the 302?
I have a drift event this Sunday and really don't feel like fixing this again its even deeper then last time and I have to work on it at my brothers house 30min away.
Any help would be great!
It's of no real help to you, but I had a 302 with a coolant leak coming out if the motor mount bolt hole (cracked block). I hit the motor mount bolt with large quantities of green thread locker and that fixed it.
I had a leak in that exact spot on one of my older 5.0's...a little JB Weld cleared that right up :)
IIRC a couple of the bolts for the timing cover need sealant as they go into a coolant passage. Maybe check those for the leak. Also those timing covers are known to crack. Summit used to have replacement covers for $100.
I didn't know about the bolts. When I swapped the water pump I did notice the bolts where wet. I don't think its craked Im pretty sure it's coming out the top from the gasket.
What type of gasket and sealant do you guys use?
I think im going ti get a new water pump at the same time. $40 at the parts store for everything I need. Sucks but has to get done.
I use black rtv on pretty much everything. Never had a 302 leak in that spot. Have had coolant pool on top the timing cover/block area but it was a thermostat gasket leak on my truck.
It's pretty common on small block Ford and Chrysler. They will leak if the cover is corroded, or if you get rambunctious pulling the pump. There could be a bunch of corrosion built up around the long bolts that go through to the block.
Every 302 I have has coolant that lives in those little divots. I haven't figured it out yet.
My 92 5.0 has been making a puddle on top of the timing cover for a few years now, right where the timing cover meets the block. When engine build 1.0 starts it may get a new cover.
I usually just use thread sealant from the part store. Its a thick liquid kinda like liquid teflon tape. I've used it a several different engines and never had an issue.
Well that's no fun... Mine is leaking enough now that its getting on the fire wall and im having to refill the system. So im definitely going to have to fix it.
So should I sand down the timing cover when I go back to install it to add some area for the sealant to really stick?
Do you have something that you trust is flat? With the timing cover off you could verify that the sealing surface is flat before reinstalling. I wouldn't use sand paper type material. A wire wheel on a bench grinder type set up works well at removing old sealant with out tearing into the aluminum. Just use a light pressure and watch where the wheel is cleaning. You'll know what's good pressure or not.
There are also the brown scuff pads that all parts stores have. Body guys use them for scuffing paint and clear. These also work well but require a little elbow grease.
I won't have access to a bench grinder but I do have some pads. And Iv got some very flat stuff at work but im going to be doing this over the weekend so thats out.
Also why would it be fine for a year and 4,000 miles then start going out?
Very common for the covers to be corroded. The cover acts as a sacrificial anode if coolant pH gets out of whack.
Yep, exactly what bentwrench said. The dissimilar metals in and iron/aluminum engine the aluminum will corrode when the coolant pH goes high. Aluminum castings can be or become porous over time as well. Aluminum is a funny animal. I've seen oil seeping through low mileage blocks due to the porosity of the casting.
Before you dig into this, can you see a trail of coolant from any specific location? Maybe even clean the engine and pressurize the system while its cold and watch for a leak. You can rent pressure testers from the parts guys. If you can find the leak for sure it could save some headache and $$.
Also could you borrow said flat surfaces from work? I would hate for you to go through all the work and the darn thing be warped.
If there are bolts that go through water passages and you didn't properly seal them , then that is likely the source of the coolant. I don't know small block Fords well enough to say if that's the case or not though but it seems like some here have said that.
There are bolts but they shouldn't contact the water they don't go through the water but next to.
spend the money on a new cover and be done with it real common problem on sbf
Skervey wrote:
There are bolts but they shouldn't contact the water they don't go through the water but next to.
I'm pretty sure a few do. I coat all the bolts and gasket with Permatex high-tack sealant.
I don't think I can get one here by Friday the only one I see on Amazon prime is $130 and there is no safe bet that anyone else will get it here in two days.
Also can i get more info on putting sealent on the bolts? is there coolant at the end of the threads that go into the block? As seen in the photo below the pasiges that go from the water pump into the block have gasket on all sides between the inlet and outlet and the bolt holes.
So when I first did the cover and water pump I used RTV that was oil resent "the black stuff" the guy at the parts store was saying that the glycol in the coolant can eat away at it over time. So im thinking that between that and having most of the bolts that hold the cover on also holding the timing cover on mabe it lost a goid seal when U did the water pump.
Im going to check the car again tonight and see if it lost a lot of coolant on the drive home from work. Im thinking it is only leaking under high rpm for now.
also how do these pressure testers work iv never messed with one?
Im guessing I need compressed air? I don't have that at the apartment. I can't even jack the car up with the people from the office working or they will tell me to get lost...
An adapter takes the place of your radiator cap and you use the included hand pump to pressurize the system.
I use the black stuff, its held up for 5 years now on my thermostat housing. Never heard of it being weakened by coolant.
Well still don't have an explanation to why after a over a year it just starts to leak with no warning.
Headed to the parts store now and ill ask about the pump!
So good news I made it to my brothers garage no big issues there other then crazy people trying to run me off the road.
SO I don't think it lost much coolant on the way over but I did run the motor up while it was hot. I reved the motor up and watched for leaks and it was hard to tell and dark and cold... But I think I saw it leaking a bit out of the thermostat housing. It looked to be dripping from there at high rpm say 4k or so. Very hard to tell with the motor running up that high and a flash light.
So tomorrow plans to go ahead and grab new gaskets for the thermostat and a new thermostat itself. Run to my brothers and get it up and running up to temp and see if I can get it to leak again to see. My one question is I have coolant on the diver and passenger side so could the only leak be coming from the thermostat housing?
