Hello there. I have a 1990 dakota. V6 2wd and here lately I've been having a lot of issue with it over heating changed the water pump and the problem persists.
Also my oil pressure has been dropping randomly.and slowly. I changed the filter to see if that would hel0 but nothing any advice?

 

A little more info might help. When does the over heating occur, always, or when sitting/idling? When you're moving, air flow thru the radiator can be sufficient for cooling, but when sitting still the fan is critical. Do you have a clutch fan, and if so, is it working properly?

In regard to oil pressure, what do you mean "randomly"? Is the gauge behaving erratically, like high sometimes, then suddenly dropping and rising, regardless of what the engine is doing? Or is it influenced by whether the engine is warm or cold, making a turn, or letting off the gas/braking? Severe overheating will thin the oil and drop the pressure, but its not clear from your initial post that the two problems are related. I'm sure you've checked your oil level, so I think my next question is how many miles are on the truck?

 

Also, for the oil pressure, check the CONNECTOR.

I started having erratic low oil pressure, so I changed the sending unit, and ... it got worse.

I then looked in the connector, and one of the two female connectors was about 1/8" further in than the other one! Checking the color code in the factory service manual, the one that was further in was the one for the oil pressure gauge.

I pushed the wire back down into the connector, reconnected, and ... I now have VERY good high oil pressure!

RwP

 

Hey Ralph, was that the big connector at the computer, or the sending unit connector?

 

The sending unit; for a 1988, there's no connection to the ECU from the sending unit.

(Nor through 1995 as far as I know.)

RwP

 

Oh yeah, I should've known better. Why would the computer care about oil pressure, that's the operator's problem , I'm just used to hearing about pushed or loose pins at the computer connector more than anywhere else.

Good to know.

 

I'll be going down the highway and it'll be fine but as soon as.i get home it'll for lack for better words start boiling. And the oil pressure will be fine then for no reason that I can tell.just start slowly dropping. And it'll stay low for a while the slowly come back.

 

Well, if it's getting hot enough that a coolant mix (antifreeze and distilled water) is boiling, then the oil would thin out, and pressure would drop. So let's tackle the overheating first.

How old is the radiator? How about your hoses? Has the motor been flushed recently?

I'd say "water pump too", but you note it's been replaced.

And here's one that strikes some as oddball - how old is the clutch on your fan? If it's failing and not locking up when at low speeds or hot, it may not be pulling air through the radiator. It's supposed to unlatch (kind of; it never completely unlatches!) when at speed because of the air being forced through the radiator by your moving. But when you're NOT moving, it's what pulls air through the radiator, so it has to latch up when the engine is at idle.

And here's one more that will make you go "Huh!" ... if you take the radiator loose (not out!), see how much crud is between it and the condensor; you may have air blockage there, so that when the truck isn't moving it just can't get ENOUGH air through the radiator.

But I'd look hard at the radiator now.

If you can find the Extreme Cooling fan shroud (yah, they're a bit rare; took me a year to find one for MY truck!), you can upgrade to the Extreme Cooling radiator (that's what the option was called in 1988; dunno what it was called for 1990); RockAuto has some new for under $140. Be aware that the one I got (the ADI) didn't have a bubble on the overflow tube, so I had to use a 360* clamp to keep it from sucking air back in.

RwP

 

Alright so check the radiator will do I'll get back to you guys thanks!

 

Crud in front of the radiator totally makes sense! Certainly would be an easy fix!!