90 Escort pinging

1990 Ford Escort
1.9L CFI
EEC-IV
35,000 miles
I noticed pinging after warm up while driving under low to medium load between 15 mph and 40 mph, once in 2nd then 3rd gear. I have an automatic 3 speed transmission. The check engine light has never come on. I ran diags and there were no stored codes in Continuous Memory. I pulled the KOEO codes and came up with a code 11, System O.K.. I ran the KOER test with no erros. I have tried an octane booster, 93 octane gas, Techron then RX2 for carbon removal, removed, cleaned and checked the EGR valve, jumped out the EGR solonoid, replaced the wires, cap, rotor, TFI module, air filter, checked the base timing and the ability for the computer to advance timing approximately 20 degrees, the idle speed and all the connections and vacuum hoses for leaks to no avail. I checked the linkage adjustment from the automatic transmission which was good. I tried holding the car in second gear longer to see if this helped with the pinging. Aside from the pinging, the car runs fine. What else could I do?

Thank you very much,

Frank

I have heard/read where automotive authorities have stated that computer controlled cars CAN'T ping..
They CAN and they DO..
In the case of Ford Escorts..mine does.LOL..it was pinging slightly on a hill 10 minutes ago.
There was a recall on some Escort maf sensors.I can't remember which.These can be cleaned or replaced..go to a bone yard and get the sensor in the housing.Change the housing with the sensor in it.
The maf goes bad or gets dirty..THEN it feeds a FALSE signal to the computer.Usually calling for a leaner condition.The computer obeys the command..leans out the fuel mixture BASED on the info it has just received.= pinging.Usualy it STILL stays within the parameters allowed by the 02 sensor.Hence no CEL. SOMETIMES..sneaky..the 02 code comes up..SOooo that gets changed..and the problem coincidentally goes away for awhile...THEN another 02..
The maf will get worse and exhibit..WEEERD! problems..you may find a maf code(soft) stored when you SWORE that the CEL never came on.

Thank you very much for your reply. Unfortunately, there isn't a MAF sensor in my Escort. There is a MAP (Manifold Absolute Pressure) sensor which to my knowledge can't be taken apart without destroying it. The tough part about this problem is that I don't have any error codes stored or otherwise. I have run the diags repeatedly to no avail. I'm beginning to think it has something to do with temperature. Maybe the car is running hotter than the guage reports it to be? I don't know. Any help would be appreciated. Thanks again for you help and the time you took to respond. I do appreciate it.
Frank
I have heard/read where automotive authorities have stated that computer controlled cars CAN'T ping..
They CAN and they DO..
In the case of Ford Escorts..mine does.LOL..it was pinging slightly on a hill 10 minutes ago.
There was a recall on some Escort maf sensors.I can't remember which.These can be cleaned or replaced..go to a bone yard and get the sensor in the housing.Change the housing with the sensor in it.
The maf goes bad or gets dirty..THEN it feeds a FALSE signal to the computer.Usually calling for a leaner condition.The computer obeys the command..leans out the fuel mixture BASED on the info it has just received.= pinging.Usualy it STILL stays within the parameters allowed by the 02 sensor.Hence no CEL. SOMETIMES..sneaky..the 02 code comes up..SOooo that gets changed..and the problem coincidentally goes away for awhile...THEN another 02..
The maf will get worse and exhibit..WEEERD! problems..you may find a maf code(soft) stored when you SWORE that the CEL never came on.

Well..I wasn't sure off the top of my head exactlly whether yours had a maf or not..BUT I based my response on others that have had pinging..or weird problems..plus the recall of these items..plus the fact that this cured some specifice problems..

Not sure if a maP could do this?

Guess we go back to the drawing board of what causes pinging

Poor fuel,
ignition timing too far advanced(what mechanisms are there to control the timing..i/e advance and retard it.),in almost ALL cases..IF the timing is retarded enough the pinging will stop.BUT at what cost to driveability,power,economy..obviouslly it can only be retarded so far.Sometimes these things are VERY hard to check when NOT under actual driving conditions..without one of those portable computers on the seat that NONE of US can afford.
I doubt you're into a weak spark condition..under load? Doubt.Worth a check.
Too lean a fuel mixture will also cause pinging..richening up will usually stop it..again..the cost.
Too hot a mixture..egr admits pretty much spent gas that cools down the incoming charge..hence controlling pinging.A non-functioning egr will cause pinging.Sometimes a remote method..either electric or vacuum is neccessary to allow manual control of it JUST to make sure it is indeed working.
Too hot an engine..a stuck/sticking thermostat in newer cars with electric fans..will keep the engine simply too hot..and allow/force the fan to make up for it.Poor circulation..rad blockages,water pump internal leakages..i/impeller slippage.Nasty! problem to trace down.A "sometimes" slipping water pump impeller.Nasty.Odd things..collapsed or collapsing(nasty) hoses.You might be able to notice a difference with the heater on full..thus more engine cooling.Drive it before it gets hot.Or let it cool and try it again when cold.
Excessively hot air intake..try it on a cool damp night.
Excessive engine load at some throttle settings..lock up convertors that don't unlock(when they should)..or are lazy/od trans that pretty much have to be driven in manual mode in city/hilly conditions.Out of o/d.
Engine vacuum low..or a lvacuum leak somewhere.

I'ldno..lol..see if I can think of any more..

mine pngs a bit..oh well.

Thanks again. I appreciate all the time you put into covering all the possibilites. I'm scratching my head because I fear doing any damage to the engine long term if I don't find the root cause of the problem before its too late. I sit up at night after work reading my Chilton and Haynes manuals hoping to find something. I've been in the computer industry for more than 26 years and if its one thing I have learned its that diagnostics are never 100%. I have an Equus 3145 Scan Tool. My computer which is running OBD I, is unaware that the engine is malfunctioning especially since I don't even have a knock sensor. If a sensor is slightly out of tolerance its not enough for the computer to recognize. I have had to break out my Fluke DVOM and check voltages on sensors to see if they are at the right voltage for different temperatures by looking at the tables for each sensor in the book. Its very tedious. OBD II is much better than OBD I for analyzing data. This car was driven by my 80 year old father-in-law who only drove it around town. That is why it only has 35,000 miles on it after 15 years. I pulled the plugs and checked the gap and the color. They were fine. I don't hear pinging when the engine is cold. As soon as the car begins to warm up within about 5 minutes, the pinging begins. High octane gasoline made no difference. Like you said, back to the drawing board. Thanks again for your help and your time. I appreciate it.
Frank

Well..I wasn't sure off the top of my head exactlly whether yours had a maf or not..BUT I based my response on others that have had pinging..or weird problems..plus the recall of these items..plus the fact that this cured some specifice problems..

Not sure if a maP could do this?

Guess we go back to the drawing board of what causes pinging

Poor fuel,
ignition timing too far advanced(what mechanisms are there to control the timing..i/e advance and retard it.),in almost ALL cases..IF the timing is retarded enough the pinging will stop.BUT at what cost to driveability,power,economy..obviouslly it can only be retarded so far.Sometimes these things are VERY hard to check when NOT under actual driving conditions..without one of those portable computers on the seat that NONE of US can afford.
I doubt you're into a weak spark condition..under load? Doubt.Worth a check.
Too lean a fuel mixture will also cause pinging..richening up will usually stop it..again..the cost.
Too hot a mixture..egr admits pretty much spent gas that cools down the incoming charge..hence controlling pinging.A non-functioning egr will cause pinging.Sometimes a remote method..either electric or vacuum is neccessary to allow manual control of it JUST to make sure it is indeed working.
Too hot an engine..a stuck/sticking thermostat in newer cars with electric fans..will keep the engine simply too hot..and allow/force the fan to make up for it.Poor circulation..rad blockages,water pump internal leakages..i/impeller slippage.Nasty! problem to trace down.A "sometimes" slipping water pump impeller.Nasty.Odd things..collapsed or collapsing(nasty) hoses.You might be able to notice a difference with the heater on full..thus more engine cooling.Drive it before it gets hot.Or let it cool and try it again when cold.
Excessively hot air intake..try it on a cool damp night.
Excessive engine load at some throttle settings..lock up convertors that don't unlock(when they should)..or are lazy/od trans that pretty much have to be driven in manual mode in city/hilly conditions.Out of o/d.
Engine vacuum low..or a lvacuum leak somewhere.

I'ldno..lol..see if I can think of any more..

mine pngs a bit..oh well.

Sure ya got enough af in it? NOT just water.Too little af can cause o/heating.
GENTLY..light with the garden hose..spray from behind the rad.Clean the fins.
A short piece of chain. Secure the hood so it can't blow up.Try it with just the outside release secured.
Still could be timing..pretty hard to check that under load at speed.Perhaps a drive on dyno and a scan could nail it.
Intake isn't restricted.
Exhaust plenty of pressure at the tailpipe.

Engine temperature and gauge.'Bout the only way to check this one..other than the old..circulation ok..not excessively hot..is to change the t/sender and make sure the gauge is accurate.OR try a seperate t gauge.

I splice into the heater hose line from the engine with a "T"(those cheap plastic water line "T"'s work ok..and a few pieces of hose..and stuff a sender in there..and run the wire or cable(mechanical) back to the car.Make sure this sender is mounted so that it is facing a bit upward(the bottom of it) so it stays immersed in coolant.

I know in the case of mine..when the factory dash gauge is JUST at the end of the normal range this translates into 210 at the FIRST point I could tap into it in the heater hose..with a s/w mechanical gauge.( I run the 2 gauges..not too trusty of factory gauges after losing a few motors years ago(not Escorts)(( 2 with factory dash gauges where the senders stopped working at.. 1.. at about 190..the other at 210..different vehicles)) Nice..gauge reads normal..toasts overheated motor.The s/w mechanical gauges are expensive BUT dead nuts trustworthy and reliable..ACCURATE! I just HATE how slow to react they are compared to the electric senders.Mine has a good heater core..new rad,w.pump,all hoses,t.stat so I know everything is ok and normal.

Ok when cold..still could be too lean once warm..

Did you change the spark plugs?..Escorts are REAL sensitive to plugs and wires.

Ok..keep us posted.

Maybe also try jumping the fan and running it on high manually..

Its funny you mention the temperature. I was sitting in traffic yesterday with nothing better to do than stare at my dashboard. I am a guage watcher, can't help it. It has saved me a few times and a few more times watching the guages of family and friends cars while riding with them. Anyway, for the first and only time ever, while sitting in traffic in gear, I noticed the temperature guage begin moving up very quickly. It moved so fast that I expected to hear grinding metal any second. My immediate impulse was to throw it into neutral, which I did. Much to my surprise, as soon as I threw it into neutral, the guage immediately moved back down to the normal area. It usually sits at about a quarter of an inch into the normal area. The fan doesn't usually kick on until the needle is about three quarters into the normal area or slightly above the middle point. The fan never kicked on and the car continued to idle and run perfectly as it always does. When I arrived home, I checked the wiring to the sender and eveything else that I thought could be loose. Nothing appeared wrong. I'm thinking the sender could be intermittent and lying about the correct temperature after a certain point. I'm also thinking its time to flush the coolant totally. The reason I haven't flushed it yet is because I get a bad smell from the heater core when I turn the heat on like there may be a slight leak. I'll also be changing the timing belt this summer because its 15 years old and I don't want to take any chances. Like you said, I don't trust the factory guage. There are no temperature markings on it to tell you what temperature you are at. You might as well have an idiot light. I would gladly change it for a better guage that mounts back in the dash where the original one is located. Its worth the money. The only decent guages I've seen mount outside the dash. I agree that the mechanical guages are more acurate than the electric ones. I haven't changed the spark plugs yet but I did remove them and inspect them for gap, color and any indication of carbon, burn, or slickness. They looked good. Just like the picture in the manual of a good burn. I did't know a spark plug could cause pinging. I replaced the wires, the cap, the rotor and the infamous TFI module because the car would stall out in the rain after driving for a few minutes. That corrected that problem. The coil is original. I'm not sue if a coild could cause pinging or not unless the spark is too small? Maybe?Thanks again for the additional tips. I may not be able to get to it this weekend since its Memorial Day weekend but I'll get on the rest of the stuff you mentioned as soon as possible. Once again, thank you for your time and the effort you spent to respond to me and address my problem. I appreciate it. Have a safe and happy holiday weekend.
Frank

Sure ya got enough af in it? NOT just water.Too little af can cause o/heating.
GENTLY..light with the garden hose..spray from behind the rad.Clean the fins.
A short piece of chain. Secure the hood so it can't blow up.Try it with just the outside release secured.
Still could be timing..pretty hard to check that under load at speed.Perhaps a drive on dyno and a scan could nail it.
Intake isn't restricted.
Exhaust plenty of pressure at the tailpipe.

Engine temperature and gauge.'Bout the only way to check this one..other than the old..circulation ok..not excessively hot..is to change the t/sender and make sure the gauge is accurate.OR try a seperate t gauge.

I splice into the heater hose line from the engine with a "T"(those cheap plastic water line "T"'s work ok..and a few pieces of hose..and stuff a sender in there..and run the wire or cable(mechanical) back to the car.Make sure this sender is mounted so that it is facing a bit upward(the bottom of it) so it stays immersed in coolant.

I know in the case of mine..when the factory dash gauge is JUST at the end of the normal range this translates into 210 at the FIRST point I could tap into it in the heater hose..with a s/w mechanical gauge.( I run the 2 gauges..not too trusty of factory gauges after losing a few motors years ago(not Escorts)(( 2 with factory dash gauges where the senders stopped working at.. 1.. at about 190..the other at 210..different vehicles)) Nice..gauge reads normal..toasts overheated motor.The s/w mechanical gauges are expensive BUT dead nuts trustworthy and reliable..ACCURATE! I just HATE how slow to react they are compared to the electric senders.Mine has a good heater core..new rad,w.pump,all hoses,t.stat so I know everything is ok and normal.

Ok when cold..still could be too lean once warm..

Did you change the spark plugs?..Escorts are REAL sensitive to plugs and wires.

Ok..keep us posted.

Maybe also try jumping the fan and running it on high manually..