Thanks for reading my post!

I'm new to this board and to Ford Trucks, I currently do though have two 5 liter Mustangs, here's some background:

I just purchased a 89 Bronco with a 302 from a friend for less than a $1000. For the most part everything (besides the obligatory north eastern rust) seems pretty good with a couple big exceptions.... The coolant is fairly milky from some sort of oil leak into the cooling system, and she has a tendency to run hot and want to over heat on rides greater than 30 miles. It also builds up what seems to be loads of pressure that actually cause the radiator to hiss in the upper passenger side when she gets too hot. Today I flushed the cooling system by adding loads of water to her running it and draining it repeatedly, then I drained off some of the water again and added coolant. I will say that the forked radiator plug was very sludged up and I actually had to poke a wire in and out of the hole to get it to drain at first.

Also my little darling has a couple of oil problems: The pressure runs fine for a while at sustained highway speeds then after 20-25 miles she starts to fall, the only way I can get it back up on the highway is to shift in to Drive from Overdrive and let her rev. This falling oil pressure situation also occurs when she is idling and warm. When I start her up from cold it takes a while for the pressure to fall off. The motor also used almost a full quart of oil today when I drove it about 100 miles, I assume it's all going into the coolant.

QUESTION:
Do you guys think it's a oil pump issue or think the pressure drop is related to the oil going into the coolant? I'm thinking it's time to pull the heads off and check if it's the head gaskets.

I also was just starting a build up on a mustang motor and I am thinking I will just re-direct this motor to my new bronco has anyone done a 347 bronco with mostly stock parts? I may just build up a 306 to save a few dollars. Do the heads interchange are their any other issues I would have when I switch the short lock plus the heads over to the bronco? Do you think the mustang cam would be appropriate? If not any suggestions?

Sorry about the long first post, but boy am I glad I found this board.

Rob Hughes
Market and Promotions Manager
Orient Express Powersports
Home of the Worlds Quickest and Fastest Yamaha Warrior
Rob@OrientExpress.com
1-800-645-6521
www.OrientExpress.com
www.TiForce.com

 

I would guess that it would heat up with oil in the water.
It might be the oil sending unit. Mine went bad in my '95 Dodge and the oil pressure would read right, then drop down, then go up again. O.S.U. only costs $10 or less......much cheaper than an oil pump.
Hope this helps.
Also a 347 should be fine in a Bronco as long as it is close to stock.

 

Five0guy, the milky coolant could be a radiator sealer. Barz-leak (sp?) will make the coolant milky. Maybe the PO tried to cover up a leaky and clogged radiator?
If the oil is getting into the cooling system you'll see some oil floating on top of the coolant in the radiator. Oil and water don't usually mix unless forced to. Also, if there was a leak between the oil and coolant, when the engine is shut down and there is still pressure on the cooling system, some of the coolant should get into the oil, making the oil milky too.
Good luck.
And welcome to FTE.

 

Sounds like a head gasket....would cause both problems hand in hand.
Time for a compression test.

 

Sounds like a good idea...i though that the compression test was something that tested the rings...or is that leakdown testing?

 

A compression test will check rings, valves and head gaskets...anything that holds the compression in the cylinder. A leakdown test will determine where any leakage is going.
Hope this helps.
Greg

 

It's really weird, but somehow I think the intermittent low oil pressure has something to do with coolant temp.

i just changed my thermostat and radiator cap and something weird happened...it took much longer than usual to warm up and during my ride home when I usually can expect the low oil pressure (when I slow down after cruising for a lil while and at stop lights/signs) she stayed within the normal range.

As soon as my coolant got up to "normal" she started acting up again. Now that I think of it she never acts up when she's cold....I will remove the thermostat this weekend to test some stuff...


Does anyone have any ideas?

Thanks again.