Exhaust popping noise on load..

[supRo]

Right I have searched and found some info but not what I'm looking for. What causes the exhaust popping noise (like an uzi going off in the exhaust? Is it fuel vapours igniting in the exhaust?

This happened to me on full boost/WOT (1.2) bar when I had to use Optimax a week ago - never had the popping with Ultimate or Tesco 99. Switched back to Tesco 99 and no popping or any abnormal noises.

 

Similarly when I had to use Esso 97 a month ago, at full boost a low thud sound occurred. Seemed to come from the front of the exhaust through to the end - Is this possibly detonation? Again when I went back to ultimate/Tesco 99 - no noises!

[Jake]

Which spark plugs are you using? What are they gapped to? When were they last changed?

 

 

 

at full boost a low thud sound occurred. Seemed to come from the front of the exhaust through to the end - Is this possibly detonation?

No, A low thudding is not what Det sounds like.

[supRo]

Which spark plugs are you using? What are they gapped to? When were they last changed?

 

 

 

No, A low thudding is not what Det sounds like.

 

I'm using Denso IK24 Iridiums. They are about 12,000 miles old.

 

I don't get any noises with ultimate or Tesco 99.

[Guest chiefvinso]

Dont the plugs need regapping after a certain mileage?

[AlanM]

Not iridium plugs, no re-gapping

[Nic]

I'm using Denso IK24 Iridiums. They are about 12,000 miles old.

 

I don't get any noises with ultimate or Tesco 99.

 

Ro, sounds like plugs are causing the missing, try a set of IK22's instead, that should sort the problem if it is the plugs. Whilst you're at it, change the plastic connectors to the coil packs as well, as they can also cause mis fire.