Engine clatter (fuel knocking)

Hi Brick,

The reason I asked is that some of the members here on PC do not recommend tank additives due to the bladder in the gas tank. If I was going to use the SeaFoam, I would lean towards the hot soak method. I have done this on other traditional ICE and seen a dramatic difference in overall ICE operation ie: smoother idle, increased performance, less hesitation. As long as you induce it whereas the SeaFoam is equally distributed to all of the cylinders, imho you should be Ok. There is a method to keep the Prius engine idling, but I do not know the trick to it. Patrick Wong | PriusChat would be the one to ask for more info imo.

Please post back with your results once you completed the applications of the products you have tried.

Good luck.

Ron (dorunron)

 

What's the issue with tank additives and the bladder? I can't think of anything offhand that would be harmful, except maybe a little higher concentration than normal due to the low volume.

If I go for seafoam I get to cheat since I have an Autoenginuity tool with Toyota OEM coverage. I'm reasonably sure I can just use that to command engine idle and shut down as needed. I would prefer not to stall it by dumping seafoam down the PCV line if I can avoid that, the reason being that if I have too much trouble restarting and the traction battery runs down I'm in for a long day. Is that what you did on a conventional vehicle or did you key-off while introducing it? I ask because I have never used the stuff before.

 

From what I have read, there seems to be a concern about possible damage to the bladder itself from the additives. I can not vouch for that personally as I have not tried any additive that is added to the gas tank at this point in the Prius.

On the vehicle that I did the hot soak on, I induced the Seafoam through a main vacuum line while the ICE was idling, then shut it down for about ten minutes. The ICE was at normal operating temp at the time of treatment.

I did note that when I fired the ICE back up ten minutes later and raced the engine as per the website instructions, quite a bit of smoke came out of the tail pipe. It took about five minutes or so of hard driving to burn all of the SeaFoam out of the system.

 

Do you typically buy E10, or not?

 

Good info, thanks. I have to believe that a material designed to be compatible with gasoline can handle detergents. We'll see how it goes. I should have some results in a few weeks.

 

Me? Yes. I don't have access to anything else.

 

Mine is pinging under these circumstances as well (slight uphill, warm weather). On steep hills it comes and goes with the throttle setting. I do my own oil changes and it's never overfilled.

I suspect I could put in some 89 or 91 octane and make it go away, but in BMWs (my experience was an old 1.8 liter that ran on 87) this usually causes the car to become "addicted" to the high test stuff and only delayed the issue because it would start pinging on the high test gas eventually. The fix for those cars is running only Chevron and putting Techron in the tank at each fill up until the problem goes away. I've tried the same solution for the Prius and haven't had any luck.

 

Resurrecting an old thread to update on other possible causes. I thought mine was pinging as well on uphills using E10 fuel for more than 2 years already. I tried using 98 octane and it did help lessen it. The engine ran smoother and could feel the additional power and didn't notice any decrease in mpgs. It did, however, hurt the wallet.

Went back to E10 and heard the pinging again occasionally on uphills. Having had enough of it, I asked the dealer if it's really pinging due to bad fuel or just something loose under the bonnet and to pinpoint exactly where the sound is coming from. Eventually they found the culprit - they said the steering column boot wasn't secured properly and was vibrating harmonically depending on engine speed especially under load where vibrations are greater. Using 98 octane must have made the engine run smoother and therefore less vibrations.
They've fastened the boot/seal securely and now the pinging sound is gone!

 

Wasn't that a recall?