Yes, I know we don't have valves....but that's what it sounded like. Let me explain.

Yesterday, I had to take my mother from San Diego to Yuma. Set the cruise at 74 (she's 80 and does not like to go fast). All was well. Got to Yuma just as my light came on. Got a bite to eat and filled up with gas. Went to Circle K gas as it was the only convienient station and traffic was a bear.

When I got back on the freeway, accelerated and at 4500 rpm, the engine started clattering very loudly. I backed off the throttle and shifted. The clattering persisted intermittently when I would give the car gas. No cel.

As I left Yuma, the clattering would come and go intermittently. Some times as the cruise control increased the load on the engine, at times when it backed off the load.

For those who don't know this route, there is NOTHING between Yuma and San Digeo. I decided to take it straight to the dealer and forgo my side trip home by way of the Sunrise Hyway, 79, 78 and finally 76 (how sad). More importantly, I figured the rattling will be horrible as I climb the mountains into San Diego County.

The rattle never got worse, in fact at 4000 rpm's the would stop. By the time I got to the summit, no more rattling. So I took the side trip.

I drove the road at high rpm's 4-7k. No valve clatter sound. It seemed to pull fine with no loss of power all the way to the beep in 1st and 2nd.

I have driven it 100miles since the cease of the clatter and I can not make it happen again and I still have 1/4 tank of the same tank.

Question - Did I just get some bad gas. It was 87. It was a different brand but I have never had a problem with 87 before.

I have 15,000 miles, no floods - that I know of, 22 months of ownership. Flashed about a year ago, 6spd. Also, still no cels.

Any other ideas? Coils? Plugs?

Mike

 

Maybe a defective cat?
My catalytic converter had to be replaced at 4500 miles... maybe your's is just showing up now?

 

ping from the bad gas at the circle k

 

^^^
Yup! Spark Knock.
Add a bottle of octane booster and stay away from Circle-K!
Next tank or two, fill up with 91 or 93 octane.

 

Bad Gas. It shows up every once in a while down here. And if you think SD to Yuma is bad, try Yuma to Phoenix or Havasu. It's like driving on the moon...

 

Chops, lived in PHx for 10yrs prior. Know the drive well.

Mike

 

wow -- im glad i read this thread because ive experienced the same thing and mistakenly thought the noise was from the slight over-fill i did on my oil. (i had to add about a quart but once all was said and done i went like a millimeter over the "full" line.

And under hard acceleration (sometimes) I would get a "rattling" sound coming from the engine compartment, no CEL's, nothing else outta the ordinary, just a weird sound a few (seemingly) random times under hard acceleration around 5K on up to 8K.

Guess I need to avoid the "regular" gas from now on huh?

Cheers,
Jeff

 

Hmm. I would have expected the PCM via the knock sensor to have retarded the ignition to prevent this.

 

As i think about it, I have once heard a knock from my (completely stock) renesis while running on BP 98 octane. hmmm.

Carbon build up can cause this too....but its not likely in my case as the motor has only 10k miles and gets to see 8k rpm very, very often.

 

The knock sensor can retard so much, and with such crappy circle-k gas, I'm not surprised you'd get pinging.

 

The thing that gets me is that it stopped while I still had half a tank of bad gas. I thought I heard it this morning but not sure. Except that one time in Yuma, nver heard it above 4k. My concern is heat. On piston engines, if they start to run warm, you'll get this condition. I was checking the temp gauge and it never moved.

I remember all the engine failures in Vegas last summer! Once I got into SD county - it was gone...

Also, the dealers here always way overfill my oil. I need to check the air filter for oil contamination - read that in other threads.

Mike

 

there is a large temp area that the guage will not move in. its posted here somewhere (by ME!) but i cant find it right now.

 

Mine does this between 4500-5500 rpm. and I'm using 91. Crappy Az gas. Since the tank is empty 2nit I'll fill up at a diffrent gas vendor.

I was thinking that maybe my plugs could be the cause since tomorrow the car will have 30k on it. I remember reading that the plugs looked really beat at 25k.

It just celebrated delievery 2 yrs ago the 15th of Feb.

 

Ye it was crappy Az gas. Went to Chevron instead.
no more rattle.
So I would say this was your problem also.

 

I filled up on Chevron 91 (highest in SD). No repeat of the loud rattle since Yuma. I've alway had a slight gargle sound as I feather the clutch out and I assumed that was the inlet ports. It's low rpm stuff 2000-3000 rpm. I assume that sound is normal.

Mike

 

Also check out whether the gas your using is blended "corn fuel" or pure.

 

Nothing is wrong with your car, but when I heard the noise 2k miles later I had to get my pressure plate replaced