Captoveur From , joined Dec 1969, posts, RR: Posted (9 years 10 months 2 weeks 20 hours ago) and read 813 times:
My girlfriend drives a 2000 Mitsubishi Galant with (I think) the 2.0ltr 4cyl engine, I know its a 4cyl, just not positive on the displacement. the transmission is a 3 speed automatic. It has about 70,000 miles on it and has had regular maintenance its whole life, eg oil changes every 3000 miles. The car just got new belts about a month ago.
Oil consumption is negligible, 1/4 to 1/2 quart between changes.
over the last few months it developed a very slight ping around 4000rpm, usually I only noticed it very faintly when getting on the highway or passing, I advised her it might be time to think about getting a tune up, she hasn't taken it in yet.
The other night I was driving it down the highway at about 70mph, 2800rpm and it started making this noise that sounded like a really bad pinging. I was thinking bad gas or something but it was happening at a low RPM. Earlier today the noise came back, this time at idle, as before it went away a few minutes later. I have decided this noise is probably not a simple ping and I am getting concerned it might be something serious, she was planning on having this car last a few more years.. any ideas what it could possibly be?
The car has no other noticeable problems otherwise and all appears fine on a quick glance under the hood. Any imput is welcome.
Dmeeky243 From United States of America, joined Aug 2004, 204 posts, RR: 0
Reply 2, posted (9 years 10 months 2 weeks 19 hours ago) and read 798 times:
hate to say it, but my dad always said knocks and pings are always bad sounds. Have you checked the tranny oil? That's the first thing that comes to my mind. Is it for sure under the hood? Couldn't be a brake or anything? I'm no mechanic, but just trying to help.
"I have a favorite dish, which tends to change daily depending on my mood, or whether I have a hangover, or whether it's
KROC From , joined Dec 1969, posts, RR:
Reply 4, posted (9 years 10 months 2 weeks 13 hours ago) and read 776 times:
Before you start dropping a mass amount of money to fix the problem, you might want to try dropping in a can of slick 50 or another fuel treatment product. I've had similar problems with my old car, and lots of times all it was was deposits inthe engine and such that were cleaned away with the treatment.
Cptkrell From United States of America, joined Sep 2001, 3220 posts, RR: 12
Reply 6, posted (9 years 10 months 2 weeks 11 hours ago) and read 766 times:
Well, it is a bit difficult to diagnose a noise on the net, but an engine noise commonly referred to as a "ping" is usually predetonation, is usually heard under throttle load and is usually caused by lower than required octane fuel for your compression ratio and/or ignition timing. Bad fuel is easy enough to detect (might want to do the fuel filter as previously suggested), altered compression ratio by carbon buildup on the pistons is, of course, more difficult, and timing is a couple-of-minute check. If a compression check indicates build up, a range colder spark plug may cure the problem...IF that's the problem.
However, you indicated that the sound was also intermittent at lower RPMs and idle recently. This could mean an easy valve actuator ("lifter") change as Lono suggested. Or...you may have a leaking head gasket. Before you do dollars large, go to:
plug in the make/model of her Mitsubishi and see if there have been any recurring problems where a Technical Service Bulletin or recall has been issued for complaints similar to yours. Regards...Jack (P.S. The above address seems to be case-sensitive, so type in as I have done above).
DesertJets From United States of America, joined Feb 2000, 7762 posts, RR: 16
Reply 9, posted (9 years 10 months 1 week 4 days 20 hours ago) and read 727 times:
I will concur with what Jack mentioned. It might be a pre-detonation problem from not enough octane. Gasing it up with premium and putting in a high quality fuel additive, something like Chevron Techron Fuel System Cleaner with an octance booster, would be a good idea for the next few fill-ups to see if that clears it up. If that does the trick then you should be fine. Some engines are notoriously bad with pre-detonation. The 3S-FE 2.0l Toyota engine in the Camry and Celica was notably bad. Back when my dad sold the things they'd come back to the shop with customers complaining about pinging early on. I suppose if left unchecked it might do some damage... though how much I do not know.
BTW... I believe that engine is a 2.4 liter.
Stop drop and roll will not save you in hell. --- seen on a church marque in rural Virginia
Captoveur From , joined Dec 1969, posts, RR:
Reply 10, posted (9 years 10 months 1 week 4 days 20 hours ago) and read 724 times:
"BTW... I believe that engine is a 2.4 liter."
On further examination I found you to be correct. I knew it was one step above lawn-boy but I wasn't sure exactly. I ran the higher octane fuel and that did get rid of what I was sure was the ping, that will be dealt with in a few weeks when she goes home, her dad is going to take it in for service.
I ran the car around the 1604 loop yesterday and was able to get it to make the noise again in an area where I could do a little more trouble shooting.
Now it is time to make myself look stupid (not that I wouldn't anyway), sure enough it was in fact, not an engine noise making the low RPM noise, it sounds like it is coming from the left front wheel. I know the car has a warped rotor because it does shake a little under braking. The rattle goes away when I step on the brakes so the best guess I can pull out of my ass is a brake pad or something vibrating in a particular RPM range. The car had a brake job about 30k miles ago and the way my girlfriend drives it may be coming due for another one in 10k miles.