Engine/Transmission (1994 - 1998) Blue smoke @ 55mph

[RWorth]

Friend of mine with a 1996 4x4 5 speed 4:10's and140k calls me and says that the truck will only do 55mph and puts out white smoke. When he lets off the throttle the smoke clears. He said that under 55mph the truck runs fine. The temps here in Oklahoma have been in the low 30's the past few days and he is plugging the the block heater in all night. Today after church I followed behind his truck and the smoke coming out of the tail pipe is blue and has a rich fuel smell. The rich fuel smell was strong enough that my wife could smell it. We followed him for about 8 miles and every time the truck would reach 55mph it would put out this blue smoke. I asked him when the last time the fuel filter was changed and he said it had been along time. So I am going to start with replacing the fuel filter. I will also check the fuel heater and pre-filter screen, if that turns out ok I have an used but good overflow valve. Does anyone have any other ideas?

 

[NHays]

Glad to see an "OK" member

Hey, sounds like your on the right track, I am leaning toward slipped timing if he has good fuel pressure after you change the filters and check everything out. I am located in Enid so if you have any other issues drop me a PM and I can come investigate also. I have a good friend in Cushing, OK. I also and plan to be over in that area next week.

 

[RWorth]

NHays,



Thanks for the reply. I am North of Tulsa about 23 miles in Collinsville. I forgot to mention that my friends truck is stock no gauges nothing. I have thought about the timing but what gets me is what would cause it to change. He doesn't hot rod the truck or anything. I did the KDP a few years ago with CPFF's tools. I have the fitting that TST sales that goes in the fuel filter housing to check fuel pressure. All I need to do now is get some hose and another 0-60 psi pressure gauge so I can check the fuel pressure. Would it be wise to check the oil to make sure there is not adiesel fuel smell? If there is a rich smell from the blue smoke is there a possibilty that there could be a slight cylinder washing going on? Just some thoughts. I really don't know if this just started or if it has been a progressive situation.



TIA.

Roger

 

[NHays]

Yeah, I would check the fuel pressure. I however doubt that you will smell any diesel in the oil, unless the lift pump is shot. I would smell the oil just in case. Does the driver of this truck idle for loooong periods of time, does he pull with it at all, what does the truck do, that will give us a good idea of the shape things are in, how many miles and has there been any pumps or parts replaced. Timing can slip for no reason, especially if when they are really cold, things can happen. I think its just a fuel pressure problem. I would even go as far as saying that if the truck has 140K on it and the lift pump has not been replaced it needs a new lift pump. But you need to check fuel pressure before you do anything to it. Then change filters and then see about the lift pump, then timing. I bet this is yet another case of what ULSD does to clean everything out, i hope that when you pull the filters they are sludge, then the problem is solved. I just kinda went through this with mine.



PS, I also have the same truck about. I had my timing checked before I had the engine rebuilt, and it had slipped to around 8 degrees, truck ran ok but hazed at higher RPMs. hope this helps.

 

[moparguy]

Blue smoke is usually oil. Check the road draft tube, ends near the starter. With all the ice and snow you guys have had it could be plugged with ice causing excess crankcase pressure and blowby.



Good luck, RJ

 

[RWorth]

Well I have some more information. It has been happening off and on and also when it does happen the owner says it feels like it is the engine is mis-firing, something to the effect like a gasser with ignition problems. Maybe this well allow some more input.

 

[bdcraig]

Sounds like when the ULSD hit me a few weeks back. Off and on for about two weeks it would miss and blow white smoke. It was usually in the morning and when it was cold out so I treated it with fuel conditioners to get rid of what I thought was water or ice in the tank and lines,(had that problem on another truck once, I don't buy fuel there anymore). Ended up getting me on the interstate one day and it was sludged up from the ULSD. Wouldn't go over 40mph and was missing and smoking white smoke like an old distillery.



Brian

 

[RWorth]

moving back to the top.



Does anybody else have any insight.

 

[NHays]

did you check fuel pressure yet, and change filters.

 

[DMcPherson]

I have seen this quite a bit here. the new ulsd diesel is eating the asphaltines(sp?) that are acumulated in the tank and lines and they end up in the fuel filter like black goo. the fuel restriction causes the smoke and low power. if you havent yet change the fuel filter. lately this is the most common problem and usually fits your complaint.

 

[RWorth]

Well,

My friend stopped by Cummins Southern Plains today and bought a new fuel filter. I offered to stop by after work to replace the filter for him, but had someone scheduled to stop by and pick the last bit of hay he had for sale. I know you are probably thinking why doesn't he do it well he is recovering from a atv accident, but anyway as soon as he gets some time I will get the fuel filter replaced and the fuel pressure checked. After ULSD was brought up I thought about the probability of this fuel causing stuff to release from the fuel tank. I really hope that we can get the filter replaced tomorrow.



Thanks again for the replies I really do appreciate it. How many times does everyone read a post that may be dealing with a problem you are having and the person who started the thread says, " I will post my findings asap" and they never do :{ . Well I hope I do a better job of posting what we find.

 

[NHays]

just moving this on to the top fellas, keeping her fresh

 

[RWorth]

Well to the 8 to 5 has kept me tied up since the last post plus trying to get in sync with my friends time havn't worked out so well, but to let everyone know he drove the truck to a friends place north east of Collinsville and the truck did just fine. Hopefully this weekend I can get something accomplished.



Have a good day.

 

[RWorth]

Well finally got with my friend and worked on his truck. First thing was to replace the fuel filter and take truck for a spin. Fuel filter is replaced and test drive was grat no lagging from 45mph to 65mph. Before filter change going from 45mph to 60mph was a struggle. Truck is running very well. The outside appearance of the fuel filter looked like the filter had been on there way too long.



Thanks for all of the responses.

 

[DMcPherson]

get someone to cut it open, I bet its full of black goo. Im actually kind of curious to know if it is or not

 

[RWorth]

I did take a look inside the filter to see the inner wall, comparing to the new filter there is something coating the filter. I will get the filter and try to cut it open to see for sure.