Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

69 351w motor drops oil pressure and gets hot!!! help

Montys69mach1's Avatar
Visiting Guest

Posts: n/a

09-27-04, 04:13 PM   #1  
69 351w motor drops oil pressure and gets hot!!! help

I just purchased a 69 mach 1 with the original 351w. I let the car warm up a little before driving it. Soon after when the car reaches normal driving temp, if I continue to drive the oil pressure gauge drops all the way down and the temp guage starts climbing. When I shut it down it leaks antifreeze. If there are any ford or motor people that may know what is causing this problem or why this happens I would appreciate hearing from you. Thank you

Sponsored Links
trinitro's Avatar

Join Date: Jan 2002
Posts: 1,915

09-27-04, 07:10 PM   #2  
I'm no engine expert, but perhaps the head gasket is leaking. A bad water pump should not affect the oil pressure, and the chance that both the water pump and the oil pump going bad at the same time is very low. Is the oil clean? Is there oil in the water?

carguyinva's Avatar

Join Date: Nov 2003
Posts: 1,147

09-28-04, 04:48 AM   #3  
whoa nelly...

...before you jump into head gaskets.

first...put a mechanical oil pressure guage on it and verify that the electrical guage is working properly...they've been known to lie. if it's not low with a guage on it...you have an electrical problem...ie a sending unit or a dash voltage regulator or even a bad guage. if it does truly have low oil pressure, then you may have oil pump wear, pressure regulator valve sticking or excessive bearing clearance somewhere.

second...on an older car like that, i'd be suspicious of the radiator before jumping on a water pump. also check the t-stat operation by removing and placing in boiling water...should begin to open just before water boils. it's possible that someone thought that removing the stat would make it run cooler...which it won't because the coolant passes thru the rad much to quickly to properly transfer the heat. checking the temp of the radiator core when it's running hot will tell you if the rad is flowing enough volume of coolant.

now...where does the coolant leak from after you shut it off? if it doesn't have a closed cooling system (my 69 didn't)...then filling it up full will cause some coolant to be pushed out during a hot soak as the system will seek it's own correct level when it's the hottest. this is why they went to closed systems with an expansion tank...so it never pulls air into the system when it cools down...the air causes oxidation. does the coolant boil or percolate after you shut it off? if so, i think you are looking at a cooling system issue.

this is not to say that you couldn't possibly have a head gasket problem...just rule out the other more likely possibilities first.

toyotaman11769's Avatar

Join Date: Jun 2002
Posts: 1,531

09-28-04, 06:10 AM   #4  
Carguyva is correct, I have a '70 and it is an open system with an overflow tube down the side of the rad.

The coolant level is about an inch or so below the neck. 351W's are not know for HG issues.

On the face of the oil guage, (the black part) see if it looks like some one held a lit cigarette next to it and is slightly melted, if so the guage is NG.

Search this Thread