240 DETONATION (was: Trying to diagnose/describe a noise)

What year 240 ? I missed the original post but you should not have a sever detonation problem. Manual or auto ? Optimax may not be the best fuel. There have been some issues reported with "oxygenated" fuels and cars with high CR. If your getting high temps you need to find the cause and not treat the symptoms. Check Rad/coolant. Engine issues (Timing ?) Ect. I live in Aust and often have temp above the 35+ mark (Not now it's winter. Brrr). I only get high temps with AC on and slow speeds.

AJS

Boris,

See, now I always thought that knocking (which I guess is the same as detonation) was a loud thump that sounded like your engine was trying to bust through the hood. Distinct single thumps. I have produced them when carelessly applying gas while starting (when I first got the car).

That's not exactly what I have here but there may be more than one kind of detonation. The sound I get is a rapid staccatto metallic gargle. I really can't describe it any other way.

If, however, we're talking about variations of the same thing, then the knock sensor really is something that should NEVER light up under normal operation and once I fix this problem I likely will no longer have a need for it. Or is it a case of this problem will now never completely go away and I have to radically change the way I drive?

blurp. ps. I'm in Toronto, do you sell the Knock sensor or can you recommend a place that I can get it?

On Mon, 25 Aug 2003 13:15:51 -0400, the illustrious Boris Mohar favored us with the following prose:

In article , snipped-for-privacy@hotmail.com by blurp dropped his wrench, scratched his head and mumbled,

[snip]

Typically when an early 240 turbo pings or pings heavily after a timing belt change, it indicates that the belt was misinstalled by one tooth. The first step would be to verify the belt timing.

Bob

On Mon, 25 Aug 2003 18:47:41 GMT, the illustrious volvowrench favored us with the following prose:

Is there something I can do to check this or do I take it back to the shop where they did the work? I'm sure they won't welcome my return if accompanied by an accusatory tone.

That sounds like you were lugging the engine.

Yup, coins rattling in a tin can.

You can get the Knocksense electronics unit from me. Does your Volvo come with the knock sensor already? Send me an email.

Occasional knock will happen under certain conditions. You may have extra load , hot day, You pull out with a hot engine and proceed to accelerate up an on ramp. It happens. If you have a persistent knock under mildest of acceleration take Stewarts advice and get it fixed. If you are running the car with increased boost and get occasional knock and would like to be more aware of it then look into my Knocksense unit. It will fix nothing but it will tell you that you are getting close. I run my 91 740 turbo to

17lb of boost and get only occasional knock if I hammer it to hard so I know when to back off. The car has been set up like that for about two years and all I managed to break so far is the M46 transmission. I wasn't even changing gears at the time. It just couldn't take the torque.

Well I've booked my car into South Scarborough Auto to have a look. I have lost faith in those folks lately but I'm hoping for the best here. I mentioned that there is detonation and overheating and that sources available to me (that's you folks) have indicated that a recently replaced timing belt should be examined first as the possible culprit. So that's what they're doing tomorrow.

Thanks to all for your ideas so far and if you have anything to add (or suggestions as to how I should phrase my description of the problem to maximize efficacy) please let me know.

I'll let you know how much they charge me and what they do.

Thanks again, blurp

On Mon, 25 Aug 2003 20:10:11 -0400, the illustrious Boris Mohar favored us with the following prose:

Just spoke with the garage and they asked if the car was overheating in stop-and-go traffic or on the highway and I said both. They told me it was likely poor flow through the radiator and the increased temperature was likely the cause of the pinging. They said they checked the timing and it was all still good.

Trouble is I think the engine pings before it gets hot.

Time for a new rad?

Thanks all for you input.

blurp

On Tue, 26 Aug 2003 12:01:38 -0400, the illustrious blurp favored us with the following prose:

When did you start to experience the detonation ? If your car runs hot then you need to look at fixing that BUT it would have to run very hot to be the sole cause of detonation. If your hearing a crackling/popping sound with normal driving in reasonable temps then you have some sort of issue that is not temp related. Detonation is a VERY fast way to kill a motor :( When does it happen ? What revs/gear/speed ?

AJS

I believe the first time I started to hear detonation was immediately after having my timing belt replaced. It had snapped at very low speeds earlier that day and I had it towed to the mechanic. When I got it back and drove it away it was making that noise periodically but I was not aware of DETONATION or that it was the sound I was hearing. Because my mechanic is not very conveniently located (and I am loathe to take my car to the mechanic and say "It's making a funny noise" without having some idea of what the problem is) I tried to get other opinions first.

These opinions were slow in coming and widely varied. Mainly because I didn't know it was detonation so I was posting questions to this group trying to get some idea of what the noise was and trying to describe it. I was not successful in describing the noise properly (no one suggested detonation here) but I eventually got someone who knew to ride with me and that's when it was identified.

As for the specifics, the problem really seems to come at around

2500rpm, regardless of gear (must be IN gear, not P or N) or speed. at about 2700rpm I can peel off a steady stream of "detonations" and I lose a bit of power. It's also been remarked by someone following me that I emit smoke intermittently and I suspect it coincides with the detonation. Not blue oil smoke. And not enough that I can see it in the rear view. I CANNOT MAKE IT DETONATE WHEN THE ENGINE IS COLD-NO MATTER HOW HARD I STOMP IT.

Does that give you any clues? I'm a bit put off by my mechanic because I took it to them and they said I needed a new rad. How do they know this? They told me they didn't test the fluid in the rad...maybe just that needs to be replaced? It's easy to just say "put in a new rad" but if that doesn't solve the problem it's $250 I'd rather not spend.

I'm tempted to take it to Mr. Lube or somewhere similarly generic to get the fluids tested. I got a coolant tester but I don't understand the readings.

A thousand thanks for reading these overly long postings!

blurp

On Fri, 29 Aug 2003 02:07:47 +0930, the illustrious "AJS" favored us with the following prose:

A million points for volvowrench!

It turns out the garage where I took my car for the timing belt replacement simply assumed that because I'm not a mechanic I must know nothing and therefore should be ignored and treated like a child.

When I returned the car to them to check the timing in connection with the detonation that started after they replaced the belt they assured me that there was no timing issue and that I must need a new radiator (assuming the pinging was caused by overheating, not the other way around).

The silver lining is that I was right to doubt their answers. I had a small non-volvo shop take a look after they (just like volvowrench) suggested that the belt was off by one tooth. After a bit of work and tuning (and advancing by one tooth) the problem is GONE! Lots of pickup, no smoke blowing, temperature back to normal, no detonation.

Thank you to all who looked at these seemingly endless posts and offered advice. Now only two questions remain:

1. Should I post the name of the garage that was prepared to start down the long road of "Let's try this next..." rather than just listen to me and treat me as an intelligent human being? They have grown and the resident "expert" seems to just oversee the work of junior mechanics.

1. Since I can't go back there (because the trust is gone) can someone suggest a reputable small shop in Toronto? Right now my first choice has become Rui at Apollo Garage (always did well before but not very conveniently located). I consider Swedish Motors equal to the dealerships.

A thousand thanks again to all you Volvo experts on this group. You make owning a Volvo (and its inevitable repairs) an enjoyable experience. You also prove over and over that there is no match for the power of problem-solving ingenuity when combined with communication and community.

Humbly, blurp

On Mon, 25 Aug 2003 11:46:53 -0400, the illustrious blurp favored us with the following prose:

A million points for volvowrench!

It turns out the garage where I took my car for the timing belt replacement simply assumed that because I'm not a mechanic I must know nothing and therefore should be ignored and treated like a child.

When I returned the car to them to check the timing in connection with the detonation that started after they replaced the belt they assured me that there was no timing issue and that I must need a new radiator (assuming the pinging was caused by overheating, not the other way around).

The silver lining is that I was right to doubt their answers. I had a small non-volvo shop take a look after they (just like volvowrench) suggested that the belt was off by one tooth. After a bit of work and tuning (and advancing by one tooth) the problem is GONE! Lots of pickup, no smoke blowing, temperature back to normal, no detonation.

Thank you to all who looked at these seemingly endless posts and offered advice. Now only two questions remain:

1. Should I post the name of the garage that was prepared to start down the long road of "Let's try this next..." rather than just listen to me and treat me as an intelligent human being? They have grown and the resident "expert" seems to just oversee the work of junior mechanics.

1. Since I can't go back there (because the trust is gone) can someone suggest a reputable small shop in Toronto? Right now my first choice has become Rui at Apollo Garage (always did well before but not very conveniently located). I consider Swedish Motors equal to the dealerships.

A thousand thanks again to all you Volvo experts on this group. You make owning a Volvo (and its inevitable repairs) an enjoyable experience. You also prove over and over that there is no match for the power of problem-solving ingenuity when combined with communication and community.

Humbly, blurp

On Mon, 25 Aug 2003 11:46:53 -0400, the illustrious blurp favored us with the following prose:

Please do.

I heard that Apollo is good. You can also try Suter's Auto Service in Aurora.

Nice to hear that the problem is solved. As far as "naming" the garage responsible for the "mistake"...... I vote a resounding "YES", & my reasoning is this,..... "word of mouth advertising is the best & worst for any business" and, I would think for them to be so arrogant that they couldn't have made an error should be brought to the attention of existing and future "potential" customers.

Herman '83 282 5.0 H.O. formerly 242 Turbo intercooled.

Hi, I think you should report this directly to volvo. I have worked in the car manufacturing branch (I develop electronics and software), and from my experiences with Volvo I can tell you that they want a high quality. I am certain they are not happy with situations like these.

Regards,

Pieter