I had to change my Intake Manifold and now that I have I was driving it right after and my oil pressor dropped to zero and would not come back up. I made it to where I was going sense the truck was driving just fine shut it off started the truck back up and it went back to where it was supposed to go and now it is either working or showing zero. I was trying to get my heat to work better with changing the Thermostat but the dumb *** who had the truck before me ****ed that all up and I had to change the Intake Manifold and now the heat is the same or worse. HELP!!!!!!

 

What vehicle we talking about here so this can be moved to the appropriate technical section? Please state the vehicle details. Year, engine, transmission, mileage, etc.

 

Its a 98 Dodge Dakota 3.9 auto. My bad thought I selected the right thread guess not.

 

Well, yah, this would be the right thread. It's just helpful to know what kind of truck you have - the best way to tackle a 3.9 isn't always the best way for the 4-banger as for the 3.7/4.7 OHC motors ...

THAT said.

Have you tried reverse flushing the heater core yet? That's a good first-stage go-to if the motor heat is high enough but the cab heat isn't (and not on Dakotas alone, BTW!)

What temperature is the engine getting to? And I'd suggest getting an OBDII scanner that can read active data streams and seeing what temp the ECU sees, not necessarily what the gauge shows (the two may not be the same!) What I've used in the past on OBDII cars is a generic ELM327 BlueTooth OBDII pod, and a program named Torque (Torque Free at first, then I ponied up the $5 for Torque Pro ... ) on my Android phone.

Is the fan motor running at speed? Does it vary with the adjustment of fan speed? There's been a few with bad resistors for the fan motor that there's heat in the dash, but since the fan doesn't blow the cab stays nice and cold.

I'm sorry to hear about that intake manifold problem. First time we changed the water pump on my truck, I snapped the bolt off for the thermostat housing. After we had the bolt EDM'ed out (after we broke off an E-Z-Out in it!) it never sealed properly with the factory housing, so I bought an after market that had a thicker flange and then THAT sealed properly. It was a pain, I guaran-darn-tee! (And I did it to myself, can't even fuss about the Previous Owner's!)

Hopefully this helps some. Let us know how it does, or does not, help, please.

RwP

 

You know I have not tried flushing the Heater Core I will have to look up exactly how to do that. I know how to use the Flush Kit that you can get from the Parts House is that the same thing?
The Temp on the truck seems its right where it should be running fully warmed up its real close to 210 maybe a little below it and now that I changed the thermostat that is where it stays at. The heat got a little better when I changed the AnitFreeze and the Thermostat but yea it still does not work great. I have hooked a code reader up to it before and it never showed anything regarding the heat just O2 Sensors and something that I cannot remember.
Its straight Fan on that truck so it runs with the motor speed without an issue.
I just really need to figure this heat thing out for my kids this winter I am hoping that it does not come down to me changing the Heater Core cause that is such a pain.
I need to figure out wtf is up with my Oil Gauge. You start the truck and it goes exactly where it should sometimes then it will just sit at zero but if the Truck really had no oil pressure it would have blowed up cause I was driving it the first time it did it. Sometimes it will not show anything when you start the Truck then sometimes it will be working go to zero dummy light comes on to check the gauges then it will come back on. I have no damn clue wat is up with that thing.

 

Why would changing the Intake Manifold and Thermostat and changing the Anti Freeze make me not have oil pressure? Now it sounds like the Motor in Knocking it is defiantly making a noise that it wasnt earlier today?

 

Not knowing what you exactly did, I can't say - but there is a belly pan on the intake that can suck oil in. So I'd bet the Magnums have oil under the intake. So it may be you've got a problem with the seals there.

You may also have a problem with the oil pump drive off the distributor, if you pulled the distributor to get the intake off and on.

The gauge could just be a problem with the wiring to the sending unit - it'd be instructive to pull that, put a T in, and put a mechanical gauge off the T also.

As to flushing it, what I meant was a full reverse flush of the heater core.

What I did on mine (and later replaced the core, but then, it IS a 1988 with 27 years on it!) was to take the hose loose from the upper intake, connect it to a 5/8" female hose fitting (one of those clamp on types from WalMart), pull the hose loose from the water pump that goes to the heater core, attached a garden hose to the 5/8" female hose fitting, and gradually crack and open the water hose to blow the crud out of the heater core. BIG keynote is "gradually" - if you it it with water system pressure up front, you run a REALLY good risk of blowing the core out and dumping water all over the interior of the truck! Start with it trickling, and keep turning the faucet handle no more than 1/4 turn at a time (presuming a multi turn faucet!) to where it keeps going up and running clear.

If all you used was a simple OBDII code reader, then you can't monitor the data streams with it. You need one that's a full scanner, that's designed to allow you to read the data streams while the motor is running. Again, I used a ELM327 Bluetooth adapter and Torque (Free at first) to monitor my 2000 Malibu. I'd keep doing it if the 1988 was OBDII ,,,

As to the fan - I didn't mean the cooling fan on the engine, but the blower motor fan that blows the air around inside the passenger cab.

What does THAT do for you? Vary properly with the blower motor speed control? Only on high? Only on speeds 3 and high? All speeds? What?

RwP

 

Thread moved into the correct forum.

I agree with Ralph on flushing the heater core. I think you'll find a lot of crud in it.

On the oil pressure, the sender might have failed. Mine died just like yours did. Verify with a mechanical gauge. If you don't hear the lifters when it reads 0 then it's probably just a sending unit - probably.

 

The Blower fan is fine it is warming up on all speeds. Didn't pull the distributor when I changed the Oil Pan but I did change the Gasket on the bottom of the Intake Manifold I have seen where people have said to look through the Throttle Body for Oil. The Gauge has been working and not working. It hasn't worked today but for like 5 mins this morning and now that I drove it to work running 65 for about 10 mins it does sound like it has a lifter knocking now and I dont have access to that kind of code reader or a mechanical gauge. Now that I replaced that I am flat broke so I guess I will just see if it blows up or not.

 

I looked through the throttle body and there is no oil on that plate that I changed the Gasket for. I also pulled the dip stick checked the oil and it is right at the full line. Started the Truck and checked the dip stick again and the oil was all the way up the stick like it should be. If it didn't really have oil pressure then the oil level on the stick would not be moving right? I am going to have to get another Gauge and check it out.