knocking ?
Thread Starter
|
Junior Member
Joined: Jan 2006
Posts: 1
Likes: 0
knocking ?
My truck makes a crinkeling knocking sound under load and acceleration. and is much worse with lower octane gas. Itook my 1998 4.6 f150 to the dealership. They said nothing was wrong, no codes. please help.
Member
Joined: Nov 2005
Posts: 88
Likes: 0
Gorilla-
OK.. Is it for the most part normal sounding at idle, until you accelerate, and then it gets loud, and even louder with more gas? If so, that's what mine is doing, and it went to the shop this weekend. My 5.4 may have a totally different problem, but at first they said it was the piston slapping the head, and now we think it may be a broken lifter spring. Either way, I never got a check engine light. I did a scan with my Predator tuner, and at first got a knock sensor code, but then I pulled the performance tune, and replaced stock, and the code cleared and did not come back. I will let you know what the shop tells me later today. I'm not trying to freak you out, but I'm sure you're worried anyway... It's just that it sounds like you have the same symptoms as me. I'll let you know.
-Rob
OK.. Is it for the most part normal sounding at idle, until you accelerate, and then it gets loud, and even louder with more gas? If so, that's what mine is doing, and it went to the shop this weekend. My 5.4 may have a totally different problem, but at first they said it was the piston slapping the head, and now we think it may be a broken lifter spring. Either way, I never got a check engine light. I did a scan with my Predator tuner, and at first got a knock sensor code, but then I pulled the performance tune, and replaced stock, and the code cleared and did not come back. I will let you know what the shop tells me later today. I'm not trying to freak you out, but I'm sure you're worried anyway... It's just that it sounds like you have the same symptoms as me. I'll let you know.
-Rob
Junior Member
Joined: Dec 2003
Posts: 3
Likes: 0
From: Austin, TX
Intermittent Pinging
Have had a similiar problem with 98 Expedition 4.6l since about 30,000 miles.
Using Preimum used to stop it, but it got to where it would do it even with Priemum. So at 40,000 I started researching.
Then, I found a post on this forum that showed how to clean the Upper Intake EGR holes. These holes allow EGR gas into the intake to "lower the temp" (who knows) .The Upper Intake is held on with 4 bolts. It's the part the air cleaner and EGR valve hook to. Anyway, my holes were 90% clogged. After cleaning them, the pinging dramatically decreased, but it would still do it alittle but now it wasn't bad enough to spend more time and money on.
Here it is 2yrs later and now I've got 152,000 miles on it. It's started that irritating INTERMITTENT ping again (now everyday). I've check the EGR holes and they are OK. O2 sensors appear OK comparing bank to bank. (Fancy Palm ODBii reader that charts various points) So now I'm at the point I don't know what to do.
I'm taking it to a shop WED 1/18/06 that claims they shouldn't have a problem fixing it. We'll see.
Carl
Oh, I wouldn't trust the Dealer to even change oil. At 30,000 I took the vehicle into the Dealer and told them to do whatever it took to stop the pinging... I didn't care what it cost. They were still to LAZY to really try and fix it. I picked it up 3 day later. They'd driven it 3.2 miles and had hooked up the Diagnostic machine. All within spec. I owed them 80 bucks and it still pinged. I did get them to lower the minumum Octane setting in the computer, but it didn't fix it.
So there you have it.
Using Preimum used to stop it, but it got to where it would do it even with Priemum. So at 40,000 I started researching.
Then, I found a post on this forum that showed how to clean the Upper Intake EGR holes. These holes allow EGR gas into the intake to "lower the temp" (who knows) .The Upper Intake is held on with 4 bolts. It's the part the air cleaner and EGR valve hook to. Anyway, my holes were 90% clogged. After cleaning them, the pinging dramatically decreased, but it would still do it alittle but now it wasn't bad enough to spend more time and money on.
Here it is 2yrs later and now I've got 152,000 miles on it. It's started that irritating INTERMITTENT ping again (now everyday). I've check the EGR holes and they are OK. O2 sensors appear OK comparing bank to bank. (Fancy Palm ODBii reader that charts various points) So now I'm at the point I don't know what to do.
I'm taking it to a shop WED 1/18/06 that claims they shouldn't have a problem fixing it. We'll see.
Carl
Oh, I wouldn't trust the Dealer to even change oil. At 30,000 I took the vehicle into the Dealer and told them to do whatever it took to stop the pinging... I didn't care what it cost. They were still to LAZY to really try and fix it. I picked it up 3 day later. They'd driven it 3.2 miles and had hooked up the Diagnostic machine. All within spec. I owed them 80 bucks and it still pinged. I did get them to lower the minumum Octane setting in the computer, but it didn't fix it.
So there you have it.
Member
Joined: Nov 2005
Posts: 88
Likes: 0
I just got word from the shop, and it turns out that my problem was not nearly as bad as we had worried... I had developed a hole in the exhaust manifold, and blown out the gasket. Easy fix, and way cheaper than tearing down the top end. I still have a very faint ticking, even with 93 octane, and it's running lean on one side, so we are gonna knock out the fuel injector and maf upgrade while it's in the shop, and then saturday is dyno tuning.
...IF EVERYTHING GOES SMOOTH.....
Gorilla, let me know what you find out... it sounds alot like what mine was doing. Good luck.
...IF EVERYTHING GOES SMOOTH.....
Gorilla, let me know what you find out... it sounds alot like what mine was doing. Good luck.
Junior Member
Joined: Dec 2003
Posts: 3
Likes: 0
From: Austin, TX
OK, picked up the 98 (4.6l) Expedition today. Independant shop checked EVERYTHING.
Result:
Carbon build-up on back of valves. (Flexible Bore scope with LED light on the end of it.)
MAF thinks it's at 2500 ft, but throws NO codes. (we're at 500ft here)
All else OK, O2 sensors(all 4 of them), fuel pressure, differential press sensor, EGR flow, and no intake manifold leaks.
Wanted the Guarantee, so had them CLEAN the Intake and Valves (3 step B&G process) $180.00
Had the MAF replaced with Genuine Ford MAF matched to the VIN #. $500.00
The MAF was like $390.00. The shop did not recommend buying a generic one. Just too risky. The Ford one would work for sure. So I went with Ford.
Anway, that's the most money I've EVER spent fixing a vehicle. It might sound HIGH, but the Bottom Line... THERE IS ABSOLUTELY NO, and I mean NO PINGING.
The shop suspects the MAF has probably been off for years, but with NO code indication. Thankfully I found what I beleive was an HONEST and reputable shop.
The END to a LONG story. If it comes back, I'll post.
Carl
Result:
Carbon build-up on back of valves. (Flexible Bore scope with LED light on the end of it.)
MAF thinks it's at 2500 ft, but throws NO codes. (we're at 500ft here)
All else OK, O2 sensors(all 4 of them), fuel pressure, differential press sensor, EGR flow, and no intake manifold leaks.
Wanted the Guarantee, so had them CLEAN the Intake and Valves (3 step B&G process) $180.00
Had the MAF replaced with Genuine Ford MAF matched to the VIN #. $500.00
The MAF was like $390.00. The shop did not recommend buying a generic one. Just too risky. The Ford one would work for sure. So I went with Ford.
Anway, that's the most money I've EVER spent fixing a vehicle. It might sound HIGH, but the Bottom Line... THERE IS ABSOLUTELY NO, and I mean NO PINGING.
The shop suspects the MAF has probably been off for years, but with NO code indication. Thankfully I found what I beleive was an HONEST and reputable shop.
The END to a LONG story. If it comes back, I'll post.
Carl