Does 98' 4.6 have a barometric sensor? 1 of the dealers that i might take my truck to, to work on the pinging problem said that i might have a bad barometric sensor. i've looked in every book i can find and can't find anything about a baro sensor. so is this guy smokin' rock or what?

 

I have developed the exact same probem and am now convinced that it's an EGR system failure, most likely from carbon deposits.

http://www.autotruck.net/ms/archives...98/1098egr.asp

Low or non-existant EGR flow will cause rough running and severe detonation.

There is a lot of info out there if you do a web-search for EGR cleaning.

My '97 with 71,000 miles is at the dealer for detonation problems right now. It was running beautifully till the temps dropped to the 40's. They drove it yesterday and told me they didn't hear anything out of the ordinary and found no fault codes.

Present plan is to ask if they have established a procedure for cleaning the EGR deposits. If not, I'll do it myself.

The ERG and the MAP (Manifold Absolute Presure) sensor work together also.

 

The EEC V system in the F-150's doesn't use a BAP sensor. The guy is a crack smoker. While EGR and carbon deposits can cause pinging, these engines run so clean that there is rarely any deposits large enough to raise compression that much. I would lean towards the MAF sensor causing the pinging. Especially seeing that you have a K&N on it. I've played this game before with my truck! Try cleaning the heated wire with carb cleaner, if that doesn't work it's gonna need a new sensor.

Hope this helps!

 

unclebeldin,

i agree w/ what you said about the carbon. i can't see how an engine like this could ever aquire that much carbon unless it was burning serious amounts-o-oil. mine doesn't use a drop.

as for the K&N it was removed some time ago and was pinging before and after i put it on. i did clean my MAF but it didn't help. did you have the same problem before you replaced your MAF? ...cold air temp = pinging w/ warm engine?

some of these mechanics make me wonder. i had 1 tell me yesterday that the engine in my probe GT was the same as the SVT engine in the contour. if they could be any more different, 1 would be from a different planet! i think this dude sniffs glue as well as smokes rock. yikes.

 

There are 2 kinds of carbon build up, 1 which is inside the combustion chamber which as stated above is rare in these engines. 2 is in the EGR loop which is outside the engine and is caused by the exhaust. Most mechanics have no clue what to do with the EGR system for instance you can fry some of the sensors just by testing them wrong! Also EGR valves almost never go bad they just need to be cleaned every now and then but for some reason they love to replace them most likely because it is easy to do.

usually chalkie exhaust carbon clogs somewhere in the EGR loop which if cleaned out should solve your pinging problem if that doesn't fix it it is most likely an intake manifold leak.

Good luck

 

The EGR system on these things are very important to the life of the engine...If they dont work well- the engine can ping and in severve cases-fry the valves....

HCMQ- hit it on the head the EGR loop is the one that needs to be cleaned....Just pull the egr valve and do a visual inspection...You can also activate it manually and see if it is working...

 

The EGR system by design is going to become blocked over time by carbon deposits.

My truck started running rough and knocking at cruising speed a few weeks ago. I took it to the dealer and being the true morons that they are, didn't listen to what the problem was. I told them that it would only knock at cruising speed, never at WOT. They had my truck for 2 days and said the truck ran perfectly ( I read the test print out and of course it says "Customer complains of knock under load".) Knock under load has never been a problem in my engine!!! . I asked them to check the EGR system for carbon build-up and stuck valves and they said everything was fine.

I knew everything was not fine so I looked into solving this myself. I check the EGR valve and sure enough, it was full of carbon.

Next I pulled the PCV tube off at the intake manifold and thick black goo oozed out of the tube. It was a mixture of raw gas and carbon by the smell of it. (I changed my PCV valve about 5,000 miles ago).

I cleaned the system myself with a carbon remover meant to be introduced to the intake manifold behind the throttle body by with the use of engine vaccuum.

I warmed up the engine and hooked up the bottle of carbon remover in place of the PCV pipe inlet on the intake manifold. I let the engine suck the chemical in for about 2 minutes and shut the engine off for 10 minutes then started the engine and allowed the rest to flow through.

After the bottle was empty I hooked up the PCV tube again, put the fuel system treatment in the fuel tank, and ran through that tank of gas a quikcly as I could then changed the oil.

My truck is running perfectly smooth again and I checked the PVC tube and EGR valve yesterday and both are clean again so I gained the results I was after.

I'm not telling anyone else to do this becasue there is a possibility of engine damage but it worked in my engine and I'm glad I did it.


I beleive the dealer does the same thing for $129.00

 

thanks for the great info guys.

AjRagno, how many miles are on your truck? just curious. also, did your truck ping only when the AIR temp droppped?

i'll definitly pull the egr off and take a look.

 

I have about 71,400 miles now.

My engine started to knock the 1st cold day of the season. The temp was around 40 degrees when I entered the highway and my truck sounded like someone was hitting the driver side exhaust manifold with a sledge hammer a couple of times a second. It started when my transmission went into O/D and the RPM's leveled off at 1500.

 

AjRango,
i don't think my pinging is anything like yours. i think it would be classified as being "light." i pulled my EGR off last night and it was virtually sqeaky clean. everything worked fine. i even pulled off my DPFE and cleaned it too. i'm starting to wonder if that might be the cause because the POS is corroded to hell. i've heard that the new 1's are plastic. i drove it afterwords and there is no improvement. the pinging is light. i don't think most people could hear it. it's most noticable if i'm in park or nuetral and i stomp the pedal. i then get a noticable pinging/gurgle and then it revs up. maybe i'm expecting too much? the manual does say that one should "...not be concerned about light pinging." i'm just glad that i don't do any heavy towing in the winter bc my engine probably would be damaged by now. i dunno.

any thoughts?

 

Since Ford did redesign the EGR valve I'm sure the original ones did have some issues.

A new EGR valve is not too expensive. About $31.00 at
http://www.fordpartsonline.com