EF V8 Ping...(Long) - Ford Forums

Shark · 07-11-2002, 14:30

Hi,

Just wondering if anyone has seen symptoms similar to these below or has any suggestions on what the problem may be.

I have a '95 V8 fairmont and it has very bad pinging around 1500 0- 2000 rpm when the engine is at normal operating temp.
When its cold, it generally goes like anything.

I think the car had a slight pinging problem when I bought it, but it was only noticed when going up huge hills and driving with reasonably high revs so I was not concerned to much with this as we don't flog it much and it was on standard unleaded fuel.

However when taking it to Tassie a year ago ( approx. 80,000 km on the clock), we were driving through some high altitude mountains fairly slowly and all of a sudden it developed this awful pinging which sounds like its coming from every cylinder.

Ever since then we have been limping the car around as it only comes in when under load at around 1500- 2000 RPM.

Water and oil look fine, although I have been loosing a slight amount of water somewhere lately and have noticed that I don't have all that much pressure in the cooling system as I can squeeze the top hose quite a bit and remove the cap without to much fuss, I did a pressure test and that worked ok, changed the cap twice and even tried a ford cap (although they are all made by cpc anyway).

I work in spare parts and I've spoken to many mechanics and other V8 EF owners and no one else so far has seen this problem before.

Out of all the the mechanics that I've spoken to and taken it to, only one has wanted to go further than the engine cover and try and find the problem, most guys claimed it was poor octane fuel but it is now running premium and never had the problem on straight unleaded until that fatefull day anyhow...

The mechanic mentioned above spent a day and half on it and found all sensors were operating to their correct values except the IAT so I put a new one in from ford as it was only $20, still no joy, he also said its a lean ping...

Diagnostics tests have returned no fault codes, Ive flashed them, driven the car made it ping really bad, checked again... no fault codes.
Although when I first checked the codes, I got some weird ones that are not listed, I flashed them, and then a fault code came up saying the left hand fan was not working but it was, flashed it and never seen that code or any others again.

Checked base timing using diagnostics port as advised in the ford manual, spot on, however the mechanic noted that he tried it by pulling the jumper pin out and it wouldnt go to the base timing figure, dont know about that, I couldnt find the jumper pin and did it via the diagnostic port.

MAF wires are spotless and it was noted that part of the plastic wiring retaining clip was previously snapped off, so it looks like someone else tried to fix it before I bought it,

We are thinking it maybe an ECU fault as it only does it when it warms up or after 10 minutes driving,(much the same thing) , and occasionally it runs great even when at normal temp, also the strange fault codes.

On one occasion whilst driving over some hills, it was pinging badly so I pulled over after the hills and turned the ignition off, waited 10 sec's and restarted the car , gave it a flogging and it didnt ping once, had to stop the car a few mins later to pick someone up and when I started it again it pinged like never before.

On another occasion recently I dove through light regional traffic for half an hour at normal temp no pinging, the car went like anything, then I went around a small diameter roundabout and as soon as i came off it it was sluggish and was pinging again.

So it appears to be an intermittent fault to me.

I contacted a local ECU guy yesterday on recommendation from the mechanic mentioned above and he said he can test the ecu for $110. if its faulty it will be $300 for it to be reco'd (no testing charge if found faulty)

He mentioned that if its a lean ping its more likely to be a O2 sensor but we checked the inputs from them and they came up fine on the cro. In fact all inputs were fine except the IAT sensor was slightly out of range so that was replaced.

I haven't taken it to a dealer as I've heard quite a few complaints about my local ones lately and my symptoms appear to be identical to those experienced by many late model V8 F150 owners in the US, these guys trucks are still under warranty and no one has found a dealer over there that has been able to fix their problem yet.

(A search on pinging at www.f150online.com reveals a tonne of complaints about serious pinging in the late model V8s in use there)

I'm wondering now if I should have it dyno'ed by someone first before testing the ECU, as the problem only comes out under load.

Any suggestions would be greatly appreciated.

Thanks
Shark

T3man · 07-11-2002, 14:52

Try setting your base timing back 4 degrees - this will degrade performance but should stop engine damage - if it works for a week then advance it by 2 degrees and test again for a week. If it is OK leave it there and live with it - at 2 degrees you won't feel any loss of power when you're driving anyway.

You could also try removing the engine temp sensor (the ECU one) and just hang it in the airflow dehind the radiator - this will make your ECU think the engine is colder and as you say the problem doesn't occur until hot then this could overcome it. Only do this if you are sure it is a lean burn pinging or your economy will drop by up to 10%.

However this is not answering the problem, just the symptom.

With all you've done I don't think you'll find the problem in the electronics - although testing all values while on a dyno may just show something that is not occuring in static condition tests off load.

you might have to look at the engine itself - do a compression test and see what your readings are - maybe your head/s have been shaved and you have too high cylinder pressure. Have you checked your plugs? - are they showing lean burn ie are they white/very pale? Is the engine due for a decoke? - there may be carbon deposits in the chambers or on valve heads.

Oh, one other thing - has the engine got exhaust extractors fitted? These can sometimes cause lean burning esp at higher revs.

Shark · 07-11-2002, 15:27

Thanks T3Man,

At this stage I'm hoping to find the problem instead of just fixing the symptom at the expense of economy and engine efficiency.

If I can't work it out, I think I might retard the timing as you say and sell it before it does get some major engine troubles from
the pinging, using a bottle of injecton treatment stops the pinging when its in the tank also.

We are limping it around for now and it doesn't ping much the way we are driving it,
But it would be nice to be able to drive it properly again :-)

Your thoughts on the dyno were what I was thinking,
Everyone thinks it must be something silly, especially with it being intermittent, its just a matter of finding it,

I was thinking that it would probably not be an engine problem because of the intermittency (sp?).

I haven't checked the fuel pressure either , although most guys thought it wouldn't be that with the symptoms I'm getting.

Plugs have been checked 3 times and replaced once, each time they looked like they came from a perfectly healthy engine.
Also replaced leads, cap and rotor

The car is all stock standard except for a k&n air cleaner in the standard airbox.

If I had carbon deposits on the back of the valves or in the chambers do you think that could cause the pinging when hot but be fine when cold ?
I've never had it done and have 125,000 kms on the clock now.

Plus that wouldnt explain the restarting without pinging or roundabout incidents I experienced I guess if it was a
carbon problem.

Shark

Jase_ELXR8 · 07-11-2002, 16:08

definatly check your fuel pressure. Could be a weak pump or a dodgy regulator....

07-11-2002, 16:25

get your coil checked out sounds like might be faulty, same kind of thing happened to my old man.

07-11-2002, 16:28

also go to Toyota and get a can of their carbon cleaner heard in past thread they have the best carbon cleaner on the market.

Jase_ELXR8 · 07-11-2002, 16:41

Quote:

Originally posted by longjohn1
get your coil checked out sounds like might be faulty, same kind of thing happened to my old man.

Check you coil at night time, the insulation breaks down and they arc to the core...

dragonV8 · 07-11-2002, 18:33

Just a thought. Have you disconnected the battery to re-learn the computer.

Jon

T3man · 07-12-2002, 00:17

I think the ECUs on EFs and later "re-learn" new after every 100 starts so you don't have to do that any more - my dealer told me this so I'm guessing it's correct.

V8 Ghia Mike · 07-12-2002, 02:12

Hmmmm....sounds like a mixture problem once the motor warms up. Have you checked the airflow meter? I had to change mine after the old one was giving problems. Would a faulty 02 sensor cause these symptoms?

I actually had to have my 5.0 rebuilt after SEVERE pinging in hot weather, all speeds and loads! Now, it was pinging all the time once warm, not intermittently like yours, so don't panic. It's just that the MAF was one of the first things they looked at. It turned out the engine seemed like it had not had an oil change for a LONG time before I bought it. The rings were stuck in the grooves, main bearings shot etc.etc. Not the sort of thing you like to pay extra for when you get your luxury Ghia!

It came with a log book stamped regularly by a couple of major Ford dealers in Melbourne......

Mike