guysandiego

I went to Autozone to get a quick free scan -- My codes are not listed for Benz but other cars are -- the other cars all have pretty similar explanations... So, I am assuming P0505 is when a breather hose was not attached... other code P0638 I assume something must be wrong with my TB... damn sensitive sensors.

Recently I have been getting the ESP malfunction message and car will only idle -- after restart it is back to normal... but on occassions the car slips back into this mode during idle --------- the idle never appears high, low or rough -- it just secretely goes into this mode.

Can someone confirm the codes? -- I dont want to take it to the dealer if i dont need to... any suggested DIY fixes?

06E55

According to my Mercedes diagnostic codes info, P0505 is "Idle Control System Malfunction" and P0638 wasn't listed. According to some search results that I have found for P0505, try cleaning your throttle body as well as checking for vacuum leaks (as you suggested). A Google search for P0638 suggests a throttle valve/actuator problem.

Velociabstract

I got the P0505 code. The upper manifold bolts came loose causing a leak at the gasket. New gaskets, a little locktite blue and it hasn't returned. Have you had the manifolds off for any reason? Did you use locktite?

Les

guysandiego

manifolds are a new idea - i will check them

Velociabstract

This shouldn't happen (loose manifold bolts) because they come with some type of thread lock from the factory. But if someone has worked on the car and had to take the manifolds off it's going to happen. If they are loose you can tighten them up but you should get new gaskets and use a thread lock liquid. Without some type of thread lock (I used locktite blue, red's too permanent) they will come loose quickly. Mine did.

Les

mekantor

I had a P0505 that came along with a gasoline vapor leak. While I was replacing the gaskets on the head covers, I had accidentally disconnected the metal vapor tube that enters the S/C by the throttle on the driver side.

jangy

The VRP logs don't use the OEM bolts and don't have locktite. Check em and see if that hooks you up!

guysandiego

i dont think the logs are the problem - been on the car for a long while with no problems -- we used lots of gaskets and the liquid paste stuff too -- sealed up very well

jangy

Cool, glad the logs worked out. They feel good?

sneakyneon

What are your TB mods? I see in your sig it says TB grinded? P505 is common on guys that have a bigger TB, the engine has an exspected tb postion that it needs to maintain a given idle rpm, So for exsample 4%=750 rpm, when you put in a 82mm it now can make that rpm at 2% but at 4% is 1200, hence the code.

Velociabstract

I hope it was clear that I was referring to the upper intake manifolds and not the log exhaust manifolds.

Les