I purchased a 2003 DII a few months ago and did an induction Seafoam cleaning a few weeks ago. Since the cleaning the truck has been idling rough at startup, but smooths out shortly after. At first I thought that maybe the O2 sensors had been gunked up by the Seafoam cleaning, but today I added some oil and noticed an orange buildup under and around the cap. I'm starting to think that the cleaning cleared out a leak. Is there any other explanation for the buildup around the oil cap and rough idle, or should I assume that I have a leaking gasket somewhere?

On a side note, since I bought the truck I have had the throttle body heater replaced, changed the spark plugs, and had the forward driveshaft rebuilt.

Thanks ahead of time, any advice will be greatly appreciated.

 

What does the oil look like on the dipstick?

Running rough: Are you losing coolant? One posibility is that you have coolant leaking into a cyliner when the truck sits. Upon start up the cylinder misses untill the coolant clears out.

 

The oil on the dipstick looks normal. I did see some misfire and emissions codes about a week ago. I don't remember exactly which but I think it was cylinder 5 and 8. Would this indicate a leaking head gasket, or a different gasket?

Thanks

 

5 & 8 are on different sides of the engine, but are on the same coil.

 

So I pressure tested the cooling system. I pumped it up to 17 psi and it lost ~1 psi over about 20 minutes. I pumped it back up to 17 psi and it didn't appear to lose a noticeable amount of pressure. I released the pressure and ran the truck with the gauge still attached. Once the pressure built up, the needle on the gauge was steady.

Is a slight loss of pressure like I saw acceptable and possibly due to something other than a gasket leak?

 

Is it a ruff idle or more like a knocking? I had a bit of knocking on start up and it ended up being a broken bolt where the maniflod connects to the exhaust pipe.

 

It is a rough idle almost to the point of killing the engine. I do not hear any knocking when it happens.

 

Perhaps a coil pack starting to go bad?

 

Is a slight loss of pressure like I saw acceptable and possibly due to something other than a gasket leak? no; it is not acceptable. could be a gasket, hose, clamp etc. I would do it again and this time pull and tug on every hose and clamp as well as checking the back of the block.

 

Ok, so I hooked the pressure tester back up and looked all over for a leak. I found coolant dripping from the front bottom left corner of the engine. I could not tell if it was something leaking from above and dripping down. Is there anything in this area that would be leaking coolant?

If it might be a hose I couldn't see I might take out the intake and try to fix it. If it is likely leaking from the engine I'll have to take it in.

I tried to take a picture of where I found the coolant dripping from if that helps.



Thank you for your help with this.