Hello. New to these boards and Volvo, but not new to working on my own cars. So far my wife and I are loving the 240 and I'm kicking myself for not buying one sooner.

However, '91 240 is making a pinging sound. It only happens when the throttle is open. The more throttle given, the louder the sound. It can be heard if the engine is revved in park or neutral, but is most pronounced during actual acceleration.

I tried getting a recording but there was too much background noise. Hopefully I'll have a chance to try again tomorrow.

Let me know what you think. Wanting to keep this car around for the long-haul.

 

Put some Premium gas in it, see what happens.

 

It was empty when I bought it. Filled with premium before driving home. :/

 

These motors don't normally ping. High carbon build up inside the engine would be a possible cause or a faulty knock sensor which is much easier to fix (change). It is on the head, driver's side, under the intake manifold. Change that sensor, let us know.

 

a badly adjusted exhaust valve could sound like a ping if you didn't know what predetonation sounds like. these motors with high miles can also exhibit 'piston slap', but continue to run for many more years.

with crappy gas and hot weather, my turbo 740 will crackle a little at heavy throttle in 3rd at middle-to-upper RPMs, basically where its putting out peak torque. my bmw motorcycle does much the same, if its hot, and you're flat out in 3rd or 4th climbing a steep grade, it crackles a little, then the knock sensors retard it and your power falls back. so did the jetta gli I had 25 years ago.

our 240 has never pinged even a little.

 

Yeah, I'm unexperienced with the b23, so maybe my intent to express the slight metallic quality of the sound led me to use the word "pinging," which I'm not sure is entirely appropriate (probably isn't predetonation).

Valve adjustment is most likely needed. The metallic quality of the sound much less pronounced than a mechanical ticking. It only happens after warming up and sounds similar to other valve train noises I've heard.

I'm putting together an order from IPD right now (odometer gear, temp board bypass, window scrapers). Wondering if I should just add the Bosch knock sensor or take it to the mechanic first.

 

No, they don't get "rod knock" which is death knell for any motor!

The b230 get "piston slap" which is quite different and relatively harmless affliction which doesn't seem to shorten the longevity of the motor; it makes the motor sound like a diesel. The later b230, '93 and newer, don't suffer from piston slap as a rule as they have oil squirters that cool the pistons and the pistons have longer skirts.

 

eerrrr, yah, that. I'll edit my original to reduce confusion, thanks lev.