compression psi

Anyone know or know where I can find the compression psi, not ratio, for a 3.0 Taurus engine, 94 year ???? There must be a general figure somewhere.. can't seem to find it in any of my manuals, only charts with high vs low #'s.. chasing down a minor ping issue...

The only charts I've seen for the Taurus are the min/max table as well.

May I ask what you've tried for the ping issue so far?

-Rod

Ping issue is mostly at speed, could happen at 35 or 75, will start pinging when power is needed for inclines, or pretty much any variance from flat road, where intake vacuum drops.. Compression test shows 160 psi on every cylinder, removed intake manifold to check condition, pretty much a waste of time, was relatively clean, sprayed it out anyway, some gunk, not bad,, sprayed out the egr passage(seemed to be only one), shined a bright light thru the egr port, could see light in the manifold.. no koeo or koer codes, mileage is consistent from tankful to tankful.. reduced timing to 8 btdc from factory 10btdc, recommended + or - 3 degrees in book, no really noticeable change... don't believe octane adjust bar on this model,, I think SHO 3.0 may have had it(octane adjust). I have the pfe egr which isn't as accurate a system as the dpfe egr, however it shouldn't play that major of a role... I'm thinking maybe I should check the exhaust tube running to the egr valve, make sure no leakage, however I don't hear any noise.. egr valve holds vacuum, evr integrity seems alright.. I'm down to thinking maybe use something such as Seafoam, GM Topcleaner, introduced into the cylinders, see if it'll remove any accumulation of carbon, then recheck compression.. or replace the egr valve for the heck of it, see if any difference, however I'm not sure if it needs to be done, I don't like replacing for the sake of it.. Dealer told me it may just be something to live with, they told me it's not uncommon, and that de-carboning may accomplish nothing. They offer a de-carbon procedure, but told me to save my money... I don't like pinging engines, my 99 24 valve is quiet as a mouse, my 87 with the evp egr was likewise no problems, other then sensor replacement, right up until I retired it with 185k

Have you tried higher octane fuel?

Are you pretty sure it is a ping and not a misfire? When's the last time the car had a tune up?

-Rod

If you can get access to a scan tool that will read PID's, look at the baro reading. We get a lot of MAF's that read the wrong altitude, either from being dirty or just failure, and cause a ping on light load demand.

When I did the compression test, I put new plugs in, cleaned the cap and rotor, cleaned the maf sensor.. I have used premium fuel as a test, no ping that I could hear, it's definitely a ping, not misfire,,, premium could offset the timing advance incurred during supposed egr flow of recycled exhaust into the combustion chambers... however, car specs 87 octane, I don't want to have to spend, nor should I, extra $$ for this issue.... talked again with the Dealer service dept, they told me it's an issue that there isn't a whole lot to be done with, seems wacky to me.. Also, maybe the gearing of the car could contribute to the problem??? At least in the lower mph ranges, say 40-50??? These cars want to get into od as soon as possible, 35 mph shifting into od, turning like less then 1500rpm, lug it up when you need to get some oomph.. once again, no codes of any type to even indicate that parts are at the minimum parameters allowed by the system.. I have to assume everything is doing it's job for the most part.

A "minor ping issue" should be addressed by a few hundred mile run @ hwy speeds. Cars today spend too much time sitting at red lights.

it might be the design of the computer program. The pcm may be advancing the timing to much on acceleration. maybe it's a lean condition causing the ping. maybe a leaking oil pan gasket is causing the positive crankcase pressure to be off. that may be making a lean condition.

Addressing the last two posts above, the car has made several 400 mi roundtrips this summer with no difference noted,, more then half of the miles at speeds of 75+mph, no I'm not a speed freak, but you do what it takes to avoid being run over... as for the last post, it's possible you're correct on the pcm issue as the dealer has told me that it's an issue with this engine,, also told me 160 psi is not a bad number, no nothing leaking anywhere, this engine is tight,, btw 77k on the engine..

Been doing a little searching around the web, came up with something that might play a part, maybe not,, seems that the mtbe additive that was removed from the gasoline also contained anti-knock additives that weren't replaced in the new re=formulations.. making cars susceptible, not all, to possible issues with pinging and knocking because they're running hotter combustion temps now with the new fuels,, some have suggested using a step or two, if possible, colder sparkplug in an attempt to counter-act these higher temps.. another thing is that the fuel and combustion chamber cleaners that are dumped in your fuel tank may actually increase the combustion temps, worsening the ping or knock problem. I don't know these things to be true, but makes for interesting reading.. as a side note, all the pertinent parts of my egr system are doing their part, I even removed the upper intake again to double-check that I hadn't possibly missed anything in the egr passage when cleaning before, which i hadn't.. there is only one port for the egr flow into the upper intake and it is, was, clear.. I'll keep searching.........

Broke down, decided to take it to the dealer this past Friday, for my own peace of mind, to let them run their diagnostics.. Guess what? Absolutely nothing wrong anywhere in my emission or ignition system, or any computer related issue. Tech did reset my timing to 10 btdc, I had retarded it to 8 in an attempt to reduce the ping,, he also told me that 160 was an excellent number, carbon was not the issue,, he was thinking maybe the valves were possibly crapped up, thought maybe an attempt at cleaning might help,,, 50\50 chance.. I hemmed and hawed a bit, then said ah go for it... presto change-o, no more ping anywhere, at least none I can hear, seems to have more get-up and go too, of course that could be because I'm happier then a pig in #!@%...

Now that you are starting with a clean system, you should consider using fuel injector/fuel system cleaner on a regular basis. I add a bottle of fuel injector cleaner to the fuel tank with every oil change. Back when I worked at my parent's shop, I saw $2 bottles of injector cleaner fix some pretty wild driveability issues on numerous occasions.

-Rod

Oh yeah baby I'm using it already, parts store up the street had some Gumout concentrated on sale cheap, I picked up a case of 12 to start... should last for a while.. I have used various in the past, but not on a regular basis,, I'll set up a schedule, every oil change sounds good.... thanks, I know you're big on the use of this item..

The vulcan will ping ... I had a bad pinging problem, turned out to be a bad t-stat.

Yeah, mine was pinging like crazy, but nothing was obvious as to the cause... turns out the tech most likely called it right on the dirty valves, he used two cans of some type of Motorcraft top-end cleaner, I don't have my paperwork handy,, it certainly did the trick.. it's quiet now even back at 10 btdc factory timing, 87 octane