Are there any common oil leaks on the 3.9l in a 1990 dakota. I have noticed spots of oil under the truck. Also how many labor hours should I be looking at for the oil pan gasket? Should the rear main be done as wellif theoil pan is also going to be done.And is there anything else I should replace while doing it that won't cost extra labor?[/align]

 

Any motor that old is gonna have leaks, probably the gasket around the oil pan or the timing chain cover, those are typical.

 

unless your losing alot of oil between oil changes, i wouldnt worry about it. change the rear main when your tranny needs changing. valve covers have been seeping a little oil on mine since about 1990 on my 89. i lose about a half quart over about 5000 miles btween changes.

 

I have a 90 has had the same issue over the years. Found the valve cover gaskets leaked at the back of the engine and the oil ran down the back of the engine and driped off. I have changed them at leats 4 times. If you do the pan gasket the yes do the main, it can be done without removing the tranny just need the pan off.

 

Yeah but i dont think its a small leak it leaves very noticeable puddles under the truck.

 

mine had a small valve cover leak that would leave a drip on the pavement and it was noticable. run your engine until it is at operating temp, pop the hood and see if you can see anything leaking...you should smell it and also mabey see a little ploom of smoke everytime (if it does) it drip on the block or another hot part of the engine.

 

You can deffienetly smell oil burning. But I cannot tell where it is coming from. I called around today and it looks to be about 15-20 for someone to look at with the dye and see where the leak is.

 

get a case of brake clean, and a bag of rags and clean it until you can see your face !. thats cheaper that that dye crap.

 

thats that i did too! i cleaned the whole engine with brakleen and rags and then watched it idle.

 

Feel around on the head between the firewall if it is oily then it is leaking down from the valve cover.