So, just purchased this truck a week ago, 130k. PO did a tuneup 20K ago, lucas rotor and cap, some blue wires, max something brand. Truck had rough idle when purchased, with exhaust leak that I have since had fixed/welded. Drove the truck 3 hours home to Columbus from Indy, no issues other than the loud exhaust, engine ran smooth.

So I run out of gas the second day, fill up all seems fine. Change out the spark plugs to Champion Copper 64's, because I started hearing a missfire/pop sound the second night. All plugs were black, prob from the 87 oct fuel he had been using, and one was wet with fuel. After starting the truck with the new plugs, ran better, but now had the miss popping continuously at idle, NOT ABOVE 1000rpms? . Midas and an indie think its sticking exhaust valve, sounds like pop into the intake. Completed the induction cleaning with SEAFOAM, now truck does not miss/pop when COLD, or above 1000rpms, once warm, constant at idle only. THE TRUCK WAS FINE WHEN I PURCHASED A WEEK AGO, WHAT HAVE I DONE?

PO stated he uses reg oil, guessing 10w30 or something of that nature. Have debated doing another cleaning, and adding some hardcore detergent oil additives to the crankcase. I know that the oil thins and the symptoms show up, so its not the death of my engine knowing it only does it when warm hot.

I WANT TO PREVENT OPENING THE ENGINE, ONLY PAID 1200 FOR THE TRUCK, THAT IM GUESSING I HAVE MESSED UP SOMEHOW.

I ordered 8 new bosch injectors from ebay, after speaking with a guy at atlantic british, he seems to think the same as I, could be dumping fuel?

PLEASE GIVE ME YOUR THOUGHTS on cleaning out this carbon that has loosened from somewhere and sticking my exhaust valves, or perhaps its just my injector.

 

I live 20 minutes from Columbus, and work in Worthington.

I'd be more than happy to come down and lend a hand. I'll shoot you a PM with my info.

 

I had sticky exhaust valves, but my symptoms did not show up at idle. In fact, there was no problem until I got out on the highway at about 55 mph or so, and the engine would start bucking like I was driving over railroad ties. It would go away other than that. I also had a few codes, but I understand the 95 DIs don't have OBDII. I believe you can still read the codes by a light flashing under the seat or something. Have you got a check engine light on ? Could be your coolant temp sensor too. If they don't work right it might run fine when cold and then run rich when warmed up. They are cheap too.

 

Actually, it sounds like your vacuum advance isn't working at all. Remove the tube coming from the vacuum advance to the intake plenum just above the throttle body on the throttle body end. Suck and blow on it. If you get no resistance, then the vacuum advance is shot (Happens almost 100% of the time on 95's after 100,000miles). If you get a bit of resistance, then remove the distributor cap and see if the vauum advance arm moves much when sucking and blowing on the tube. That'll be final confirmation of the likely problem. The fact that you're popping below 1000 rpms, but then nothing above 1000 rpms - would point directly at vacuum advance.

A temp solution until you replace the vacuum advance is to loosen the distributor bolt and turn the distributor counter clockwise about an 1/8th of a inch (just barely). That should clear up your popping at idle and below 1000.

 

No worries, he called and I got him the number to a really good mechanic.

 

great, spike told me I probably need my timing adjusted.....i am going out to check he vac advance now.

 

Here is a little update!

Lee brought his truck up to my station this evening after I got off work, and I had a listen. At first, it sounded to me like a rod knock. I had him shut it off, and I checked the oil. Luckily, there were no signs of metal flakes in the oil, which is definitely a good thing.

The noise that is happening is definitely a "Putt Putt Putt" type noise that can clearly be heard in the upper intake. We had a look inside the oil fill hole, and there was all kinds of **** baked in there...it was downright nasty looking. A quick phone call to a friend of mine reinforced my suspicions of a stuck open intake valve. We also discovered (no pun intended) a DTC #19 on his diagnostic display.

So, my suggestion (backed up by a bunch of other people on random forums) was to replace a quart of his oil with Marvel Mystery Oil, and to add a bottle of Seafoam to the crankcase as well. Some here might scream "Snake Oil!!!!" but I'm no so inclined to agree.

The paramount thing is going to be to get that sludge out of there, so Lee said he's going to add the MMO and Seafoam tomorrow. Second, he is going to do a compression test tomorrow just to check and make sure that he has a valve stuck open. I'm gonna quess that he has little to no compression on his #8 cylinder.

My suggestion to Lee was to add the MMO and Seafoam, drive 100-150 miles, then to change his oil filter. Give it another 400-500 miles, and change his oil. He is going to keep me updated, and we'll see what happens.

~Aaron

 

yup, once I looked in the valve cover fill hole and saw literally GUNK baked on, i wondered wtf I had not bothered to look in there before, knowing that I was told of a possible sticky valve!

we will see how this all goes tomm!

 

I missed your phone call earlier Lee, sorry.

We spoke on the phone last week and I mentioned getting the timing set.

If it is a severe sludge problem then I would add Seafoam only or MMO only and not the two combined.
Then drive for 200 miles and change the oil and put in a diesel oil, drive for 500 miles and change it again.
Diesel oil has a very high detergent level and is alot cheaper than full syn which also has a high detergent level.

This does make sense, 87 octane and cheap oil in a Disco equals severe sludge build up.

I will call you tomorrow Lee.
And we will keep everyone on the forum posted.
And lets give a huge thumbs up to Aaron for helping out locally.

 

I say the best option for now would be the MMO then Lee. Lets concentrate on getting that valve unstuck.

Save the Seafoam for when you actually change the oil.

I would definitely still count on changing the oil filter after 100 miles or so...that MMO is going to knock all kinds of crap loose.

As for not looking in the oil fill hole, don't worry, it's usually the simple stuff that slips our minds the quickest...I felt like a dummy for not telling you to get the compression test LOL!