Engine Detonation

[bfrombeebe]

Hey, guys. New to the forum. Just picked up my '94 2 door sport 5 speed about a month ago. It only had 104,000, and is in pretty good overall shape. I have a couple of questions. One thing I have noticed is that when I am under acceleration, I notice some engine detonation (pinging). My question is, has anybody else had this problem, and is there something I can do to take care of this. Also, this truck has manual locking hubs and the buttons on the dash for 4wd and low range. My question is, would this truck have had auto locking hubs from the factory? Thanks for looking and I hope to learn a lot from you guys.

 

[george]

Hi

You truck did have the automatic hubs and replaced with manuals. So of the reasons why the change in hubs is because of cost, manual are soooo much cheaper and manual hubs are more reliable.

Now my 94 explorer runs great with 94k miles and also knock and pings. I have a friend who works at FORD and stated to put premium fuel in and it will eliminate the problem because it's cheaper to put premium gas than trying to find the problem. I also had a 92 explorer and had the same problem but solved it when I had to replace the intake manifold gasket, typical problem, and cleaned out the whole intake system because of all the carbon. After this fix I can use regular gas without a problem.

My 2 cent worth

 

[unclemeat]

Welcome to the site. You should not have any premature detonation. I would first try a high quality injector cleaner, check the air filter, vacuum leaks. Next thing would be to check the computer for engine codes. If it persists then do additional research (search freature) on this site.

It is posible your explorer came from the factory with manual hubs, mine did. However, it was my understanding that only manual shift transfer case equiped explorers came with manual hubs. Consider yourself fortunate, the auto locking hubs are garbage.

 

[93TwotoneXLT]

Mine does the same thing sometimes, been doing it now for about 5K. I know that my intake gaskets are leaking but with work just haven't had 2-3 days to commit to fixing the problem. If you pay attention to your coolant level and you notice that it is losing just a little bit over the course of a couple of weeks then you probably have the leaking intake gaskets that these trucks are notorious for. If you are not losing coolant then it could be a possible fuel pressure regulator, MAF sensor, O2 reading wrong, etc. If it is the leaking intake gaskets and you are not losing too much coolant then try running 93 octane with some good octane booster, then run 89 until it comes back. It also helps to take out the #5 spark plug and clean it once a month during all of this. I have found that doing these things keeps the pinging at bay for awhile until you can get around to fixing the problem. I am currently losing about a cup of coolant every 1000 miles, and can run 89 in the tank for a month or so until the pinging comes back. If you start losing a cup a week then it is time to make time for the repair. Hope this helps

 

[Brock94]

Search "Seafoam" and use as instructed to solve your pinging problem. It worked great for me and for $4-5 it is a lot cheaper than running premium fuel.

 

[ricco750]

Regarding the detonation...I had this problem over the past two years...I replaced the MAF sensor, did the SeaFoam, still pinged. I took it to Ford...the EEC checked out fine...but they told me to change my spark plugs, as I had installed the Bosch platinum 4-prongs. I changed the plugs to the correct Motorcraft platinum plug...no more pings.

 

[ma96782]

All of the suggestions (above) are good ones.........explore those avenues of trying to get this fixed.

New USED Car Owners….advice:

IMHO.....for those that have just purchased a USED vehicle from someone/some car lot (questionable history) and have noticed some issues...............

IMHO, may I suggest a complete tune up. Include the: air filter, motor flush and re-fill w/oil and new filter, fuel filter, pcv, cooling system flush and re-fill w/ new coolant, plugs and wires, run some sea foam, and don't forget the fuel system cleaner added to the fuel.

Clean the MAF and IAC……it’s a little more involved:

Explorer Maintenance

http://www.explorerforum.com/forums/showthread.php?t=144066&page=1&pp=20


Explorer MAF cleaning

http://www.explorerforum.com/forums/showthread.php?t=154711&highlight=cleaning+mafs



IAC Cleaning:

http://www.explorerforum.com/forums/showthread.php?t=84220&highlight=iac



And, another IAC Cleaning thread:

http://www.moddedmustangs.com/cleaning-your-iac.html



IF you feel energetic........do the transfer case, frt diff. and rear diff. Expand that to a check of the breaks, bearings, trans mounts, motor mounts, shocks and RAB (for the 1 Gen Explorer). Anything else....feel free to, "just do it."

Check for codes. Get a “base” to work off of.

Aloha, Mark

__________________

PS.........Ping.....as you know.....is detonation.

In the old days is was: low quality of gas, or too much advance timing, or carbon deposits, or high compression. Anyway, the MFNs put in "knock sensors," to try and combat the problem.

So, perhaphs.....it's the "knock sensor," among "other possibles."

Aloha, Mark

 

[msmith65]

Knock, ping, detonation, clatter, preignition. I've been trying to cure this in my '93 Ex since I bought it two years ago. Seafoam, MAF cleaning, higher octane, resetting the computer -- nothing would get rid of it.

Finally I took a hard look at the intake hose where it joins the MAF. Apparently a previous owner had not gotten the sleeve onto the hose correctly, and there was an expansion gap about 1/8" wide exposed, letting air into the intake stream after the MAF.

So the engine was running lean this whole time. Probably a factor in some overheating issues I'd had over the previous two summers.

I pulled the sleeve and reinstalled it correctly. With the intake stream tight, I now have no knocking. In testing, I heard only a slight ping accelerating uphill with AC on at freeway speed in warm weather -- the ultimate test, and that was on 87 octane.

I hope someone else can learn from my experience.

 

[mikeinri]

Despite what lots of people on these forums say, auto locking hubs are most defintitely NOT garbage for daily drivers. My auto hubs have 264,000 miles and counting. They have minor drawbacks (need proper maintenance, truck needs to be moving to engage/disengage), but they do offer the advantage that you get to stay warm and dry when you need to engage them.

Having said that, if you have manual hubs on there and can live with getting out of the truck to lock and unlock them, I wouldn't spend the money to go back to autos, unless you can find some cheap used ones (ebay or junk yard).

Mike