Engine Pinging Again

Hi everyone,

A few month ago I opened up the Upper Intake Manifold on my Windstar to clean the EGR Ports (Pinging issue) and to inspect the Coolant By Pass Tube that sits underneath the Plenum because I noticed a wet spot coming from around that area. The Tube itself looked fine and no signs of leaks coming from there but I did noticed some oil in one of the Isolator bolt holes that connects the lower half of the Upper Manifold to the lower Manifold (The one directly above the PCV Intake Port). Anyway, at the time I also noticed that one of the Retaining Clips for the IMRC was broken so I disconnected the arms and made sure to close the Butterfly valves they attach to (would repair later), and proceeded to assemble everything back up. The Vehicle ran fine and I had no Pinging issues at all until yesterday when I re-opened the Upper Man. and replaced the IMRC clips. Never had a CEL.
As a side note. I have been running Autolite Double Platinum APP765 for years now and I know that they have been substituted with APP105 since then. Could this be whats causing my issues? Or could it be something else?
I thank you guys in advance for your comments and recommendations.

Can you explain when the pinging occurs in more detail?

pinging occurs under load and acceleration. Thank you for your reply.

pinging occurs under load and acceleration. Thank you for your reply.


Does it does it ping from dead stop or does it seem like the tranny does not down shift and then pings? Have you double checked that everything is assembled correctly and have not forgotten to hook up something? The only repair is that you removed upper intake to repair runners correct.

Did you separate the throttle body from the intake manifold? ... and clean that area?

aside from what the other folks have said, I know these windstars are super particular about plugs. I only use OEM ones from Ford, and find them very competitive price-wise so if you haven't switched plugs out, that might be worth a try. When I did my last tune up I had some pinging and installing the new Ford plugs took it right away.

The van seems to ping only while in motion, not dead stop. On the Highway, when gunning it, I hear the pinging or when it's going up a hill and I accelerate to maintain speed. Again, when I had the IMRC disengaged I had no problem. 12Ounce, no I didn't separate the Throttle Body from the Manifold. I did clean the EGR Ports and Butterfly Valves with some Throttle Body Cleaner.

aside from what the other folks have said, I know these windstars are super particular about plugs. I only use OEM ones from Ford, and find them very competitive price-wise so if you haven't switched plugs out, that might be worth a try. When I did my last tune up I had some pinging and installing the new Ford plugs took it right away.

I know, that's why I'm wondering about the Autolite APP765 that are in the Engine now and if that could be the cause.
BTW, I replaced the DPFE from the old silver one that was on there.

Those plugs should be fine; they're the same as OEM.

On my '96 3.8L, the Autolite brand of double platinum plugs worked just fine.

One test that you might try......disconnect the IMRC and fasten them closed again......see if the pinging goes away.
You will have less power.....but better fuel economy.....but I am suggesting this to see if the pinging is related to this or not.

IF the pinging is related to the IMRC being open......then it is possible that the computer (PCM) learned the driving details while they were closed....and needs time to relearn the details for when they are open.
It is a long shot....but something to consider.

As someone else mentioned......look around to see if anything is disconnected or got bumped loose.
Also inspect the condition of the vaccum lines.....particularly the one going from the PCV valve to the upper intake manifold.....it can become soft and/or cracked from the years of exposure to oil and heat.
I have seen them crack on the inside of the elbow at the top of the intake manifold...and also become soft and collapse under vaccum conditions.

Ill give it some time and see if the PCM will make adjustments. Ill post any results as they occur. Thank you all for your help.

The van seems to ping only while in motion, not dead stop. On the Highway, when gunning it, I hear the pinging or when it's going up a hill and I accelerate to maintain speed. Again, when I had the IMRC disengaged I had no problem. 12Ounce, no I didn't separate the Throttle Body from the Manifold. I did clean the EGR Ports and Butterfly Valves with some Throttle Body Cleaner.

I have a 98 with the 3.0 engine (225k) and have the same problem, I have noticed that when it pings the transmission has not downshifted properly thus causing it to lug and cause the pinging. I accelerate harder and the transmission downshifts and pinging stops. I have done plugs and wires, fuel filter, new pcv valve, grommet, and hose to intake, air filter. Safoam trans tune with no change. I am going to change Throttle Position Sensor next and see what happens.

I will post any fix when I find it and please ddo the same if you solve the problem.

I have the same problem....its carbon build up from that troublesome oil/pvc issue....93 gas seems to help....I am still trying the oil catch idea ...not been too successful...

I will be leaving on vacation tommorrow and will not use the van but When I return, I will post any updates. Thanks for your comments.

If it was fine with the imrc arms disconnected, perhaps the imrc actuator itself isn't working. You could always try replacing with one from a junkyard to see of it helps. Did you disconnect the battery to reset the PCM?

Several times when I've read about engine pinging starting overnight, the problem turned out to be a dirty MAF sensor. You might want to take a look at it and clean it with MAF CLEANER or, in case you can't find it, NON RESIDUE electric contact cleaner.

It should be a quick easy check, my two cents...

Oscar.