Pinging problem with 2000 A4 B5 1.8T when hot

[Lwlm586]

Hello guys, I've joined the forum seeking for some help and answers, as the title says, i have a pinging problem with my Audi when its hot, i live in Tenerife so the summer has just started and my car is suffering from it.

When cold, he runs perfectly, has pull, you can hear the turbo spool, the exhaust note is great and the engine has a sexy grunt,but when the water temp is starting to reach 90º (mid of the dial) the car becomes slower, has lower torque, the sound of the car changes, you can't hear the grunt, just a plain or dull engine sound, you can hear a pulse in the exhaust note ( like a dun, dun, dun, dun, dun, dun, dun), and last but not least pinging from 2200 rpm to 3000, and when very hot he will keep doing it higher int he rev band, but i don't drive it too much.

Yesterday i was checking the MAF and it looks "new", and out of my endless curiosity i could see that the car has vacuum leaks, the first one in the secondary entrance to the air-box (it was disconnected), another because someone ****** the air filter and dented the square foam that seal/touches with the plastic cover, another one in the N75 (the long nipple it broken, so its loose), i've found a duct taped hole in the plastic tube of the return hose that go from the DV into the turbo, and a small vacuum line that goes from the lower part of the intake manifold to the DV.

I've ordered the new N75 to Audi, i'm fixing the DV small vacuum hose, also the secondary air-box entrance, the foam of the air filter is an easy fix too, i'll have to leave the DV-turbo hose to a later time... (i know this duct taped hole is/may be leaking unfiltered-unmetered air into the engine) :-(

As for the pinging i'm thinking in replacing spark plugs to a colder ones, 98 octane fuel (i'm using 95), bigger intercooler, seafoam.

I don't have acces to vag-com, do you think what i'm doing will fix something? has someone else had the same pinging problem?

 

[aragorn]

Stock engine shouldnt ping at all. even with sky high IAT's it should just reduce boost and ****** timing etc.

Fixing all the leaks has to be a starting point though.

You need VCDS or similar to find out whats going on.

BKR6E or PFR6Q are the plugs you need, no need to fit anything else.

 

[Lwlm586]

Thank you for your answer, I was thinking that perhaps the leak from the DV-Turbo was getting hot unmetered air to the engine and this made him run bad when hot, also the car runs extremely good when cold, he behaves like a beast, even with all the leaks, is there a way to know if my car is modded? chipped or something? and what can you recommend besides VCDS? as i just gave it a look and the price range goes from 99$ (for pre 2006 models lite version) to 1.249$.

Also i need to buy the return hose that goes from the DV to the turbo intake pipe, where can i get the part number? o a photo of it? i'll go to Audi on Monday to get the N75, but i'd like to have the part number to call then and ask if they have it.

I've uploaded an image that shows the location of the hole, now i don't remember if my car has a full hose or an "L" shaped hard plastic hose, also the image doesn't show the broken DV vacuum line.

I've found an online parts catalog!

 

[aragorn]

ebay VCDS lead and the free version of the software will be enough to let you scan for fault codes etc.

Any leaks will make the car run badly, the MAF is used as the main input for ignition timing and fuelling, so a leak allowing air to be drawn in without flowing thru the MAF will play havok with the running of the engine.

Fix all the pipework, and few a new DV while your in there, they're cheap and frequently split if they're old. Theres a couple versions of that DV pipe and i dont recall when they changed. Early cars had the DV mounted up high, later ones had it mounted down the bottom as per your pic. The dealer will do a VIN lookup to find the correct part, or goto a scrapyard and get one that looks the same as yours.

 

[Lwlm586]

ebay VCDS lead and the free version of the software will be enough to let you scan for fault codes etc.

Any leaks will make the car run badly, the MAF is used as the main input for ignition timing and fuelling, so a leak allowing air to be drawn in without flowing thru the MAF will play havok with the running of the engine.

Fix all the pipework, and few a new DV while your in there, they're cheap and frequently split if they're old. Theres a couple versions of that DV pipe and i dont recall when they changed. Early cars had the DV mounted up high, later ones had it mounted down the bottom as per your pic. The dealer will do a VIN lookup to find the correct part, or goto a scrapyard and get one that looks the same as yours.

Thank you man, my DV is mounted/hidden as in the pic, I'll post the results after repairing the leaks and replacing the bad pieces!

 

[Lwlm586]

Hey guys, I've finally and hopefully fixed the vacuum leaks I had, here's a pic of my old N75.

Can somebody explain the con's of running like this?

I haven't had an opportunity to take the car for a full test ride, today I think the turbo spooled a bit more than before, but I only could drive it for 15 minutes.

Tomorrow I'll have to do the trip that makes the car do the pinging, I'll let you know how it behaves.

 

[aragorn]

cons of running like what? With the break shown, the boost control should be uneffected, but the hole in the TIP would act as a leak thats bypassing the MAF. However given you also have another bigger leak in the DV line, it probably wont make any difference.