I have a 98 f150 XLT, 4.2, 5-speed, with 28k miles. This is all factory and it won't run on 87 octane, regardless the brand. It knocks and pings terrilby. Yesterday the dealer replaced the MAF sensor and told me to fill it with 87 octane. I did and it is still making spark knocks (sounds like lifters chattering) on accleration. My neighbor (long time ford mechanic) and two dealers are scratching thier heads and saying it should run on 87 octane. The engine is a windsor and I recall hearing that the old 351 windsors had a similiar burn problem. Does anyone have an idea. I have little time left on the warranty and I'm getting tired of the dealerships-they did ruin my 97 4.2L with the coolant gasket recall snafu. I am thinking I should go to a performance shop and let them try thier hand at it.

 

try switching brands of gas.Some gas brands have really low energy content.I have one particular chevron station about ,2 blocks from where I live, that i refuse to get gas at.Knock and ping terribly bad.Even on the plus.You might want to go to the computer chips forum and ask Mike Troyer about good brands of gas for your area.

 

I have the same problem with my 4.2l and ford has done nothing about it, and I have 113thousand km and they always put it on the computer and find nothing. Check the exost pipe and if it is black and suttey there is a problem. My truck has that and ford said that I'm puting in diesel so I went and gased up somewhere else. It did not help. So my truck is going in on the 2nd of Dec. Ford said it is pinging.

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99 XL 4.2L, 3.55 Limit slip, Alum. rims,
Captins Chairs, Long Box
Headlight covers, Master flow muffler,
It is one hard working truck!!!

 

Do a search in this forum for " what color is your tailpipe" You will find most of our trucks have the wonderfull sooty tailpipe. It might not be related to your problem.Personally, I think the black tailpipe thing is related to an incomplete burn of the gas. A few people in here have installed aftermarket ignition systems and they quit having the black tailpipe.Hotter spark= better burn= no black tailpipe.Just what I think and I am not an expert.trying to help

 

One very interesting thing I found out recently. I have a very similar pinging problem.. it is not as extreme though. I spoke with a service manager at Ford in Ontario. Apparently the only way to fix the pinging (other than replace the engine which they won't do) is to adjust the timing. This can be done and I will be having it done to my truck end of December.
I recommend that you speak to an actual mechanic and see what he things of adjusting the timing.

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Paul Lefebvre
Partner - Autonet Performance
www.autoperformance.net
paul@autoperformance.net

 

This seems to be the general problem with Ford waranty. Ford makes an amazing product, but their service is terrible. I would highly recomend that you just simply take it straight to the rep if you can. The only reason why I am able to obtain inside suport from Ford is because of a very close relative who works for Ford .

 

Thanks for the info. I do have some soot deposits on the tailpipe. I have told the dealerships service manager that I am going to take this to the regional ford rep. if they don't fix it.
I'm giving them another chance to fix it, but I won't be shocked if they don't. They didn't even test drive it before or after they replaced the MAF sensor, but I suspect it's the slacker attitude that is so prevelent here in florida (the techs just didn't want to expend any effort to find the problem)more than ford motor corp. not being able to fix it. I have a dealer close (2 miles) to me that refused to look at it and said to burn 93 octane, even though the manual says 87.
So, I may have to go to a private shop. The dealers just don't seem to care here, unless you threaten to make a major issue of it.

 

I've allways run the "supreme" gas 93 octane in my 4.2L and have never had any spark knock or ping. I've got several friends with V8 engines that run lower octane fuel and have the knock or ping off and on. It cost's a little more, but not having the frustration of the noise is worth it to me.

I've installed a Superchip in the last 6 months (and it requires 93octane fuel) and have noticed increased power.

You mentioned having a 97 4.2L that Ford ruined with the coolant gasket snafu. Did the dealship screw it up or did the coolant leak damage the engine.

I had the leak and took it in right away 2 years ago. The dealership proceeded to break the timing cover, take 2 weeks to get the parts and put it back together again, reflashed the computer so it's no longer the original programing to fix a cold start problem, which took my gas mileage from a solid 17mpg to 13-14mpg, put a dent in my door, bent my front license plate, and broke off plastic ears on the dash parts while replacing the washer switch. And this was all one trip. I took it back and they said they "tested" and they estimated the truck was getting 18.9mpg, and that I couldn't prove the dents were from them. I took it to another dealer and they refused to look at the truck for a poor mileage complaint unless I was getting a check engine light. Also, six months later I realized the first dealer had taken out some brand new Bosch plugs I had put in with some motorcraft plugs for the 98 model truck (the shank on these plugs was a good 1/2 inch longer than the right ones).

Anyway, it's out of warranty now and I won't ever take it to another dealer to give them the chance to f#%k anything else up.

 

99+ 3.8 Mustangs and Windstars have the same problem. A TSB has been issued and was supposed to include 4.2 F150.

The 3.8 TSB was listed under OASIS No. 9865 w/ a valve cover replacement part no XF2Z-6582-CA.

To explain quickly the problem... Apparently the baffle under the the PCV valve in the valve cover has a hole that is too small and actually is pulling oil out of the valve cover into the intake, so it is in the mix with the air and fuel when it reaches the chamber. This is causing the spark knock, and the excessive black soot on tail pipes, etc. When I took the heads of the 4.2 LB I bought, there was very excessive black residue on the pistons- ignited oil.

Mustang owners have had a hard time getting the dealer to start to recognize the TSB, since it is so new. Might want to go to the dealer and check it out. I think that TSB are only free while the vehicle is under warantee, so you might have to purchase the new valve cover- since it is not a recall. But I urge you to get it fixed- excessive knock leads to engine damage eventually.

 

Greetings all, I own a 99' f150 excab 4.2 with an auto, and I've had the knocking and pinging problem since the month after I purchased the thing. One of my best friends is a ford tech (though he tends to only work on lincoln/mercury due to his place of employment) and he initially encouraged me to take the truck in and get the PCM reprogrammed. Well, I decided to take a different route and use record keeping and experimentation to determine the circumstances that this is occuring in.

Down here in New Orleans, the weather is usually warm and humid. That combination tends to make gas burn slower, inhibiting knocking/pinging (or detonation for you old timers ). During the late spring, summer, and early fall, I never hear a peep out of the engine, even running the cheapest gas from the cheapest stations that I can find. Once the ambient temperature drops below 80 degrees, and the relative humidity drops below 65%, the pinging and knocking starts. It comes in at first during acceleration, but, gradually builds to include any times when the engine is under load.

I experimented with fighting this in several ways, from using plus unleaded, to using a mix of regular and premium, to a minor tune up. I have found that the engine will run fine on 99% of all days with plus unleaded. On the coldest and dryest days (I can't statistically unlink the two because of a limited sample set) only premium will work. I will never voluntarily put an octane booster into my gas.

I brought this to my friend, and we concluded that the auto timing advance in the PCM was pushing the timing a hair too far. The fix, of course, was to do a reprogram and have it retard the timing a bit. Well, we all know what retarding the timing does for an engine, and being the performance freak I am, I decided to keep it the way it was. You see, the rest of the engine is working fine, and I have no reason to want any of it changed. Plus isn't that much more per fill-up, so it doesn't really bother me. Plus, I like to think the engine is just a bit more peppy because of this.

One day, when I get a little money, I'll probably get a FIPK and a chip (I like the stock exhaust for now) for that extra little kick, but, after all, it is a V-6 in a truck :P

NOLA

P.S. I have heard of the same phenomenon in the 5.4L as well. They tend to like plus better than regular and, as one of my other friends discovered over two months of record keeping, get about a mile more per gallon on it.

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99 F150 Styleside Extended cab 4X2 auto XLT
Just a K&N, everything else is stock.

 

The dealer de-carbonized the injectors, but the spark knock still occurs??
I have learned that ford doesn't seem to understand it's own machines. I suppose it's an expensive lesson I've learned-don't buy a ford, they aren't what they used to be, and you are on your own if you have problems.