paulpas

I'm losing steam on my 90 V8Q. After just needing TLC, some surface rust repaired and fluid changes, the throttle stuck wide open after I thought I lubed the bejesus out of it last summer.

Since I recently moved the car is sitting under snow waiting for me to shell out the money for a mechanic to fix it. It's spending time or money and I do not have the time, thus money. The engine runs great though at 123k miles on it and the chassis! I'm located in 53168. Does anyone want to take it off my hands? My loss is your gain, I bought it for $2200.

Maybe all I need to do it to get a pep talk from you guys to inspire me to continue onward on the money pit...

V8BOB

The answer to your problem is that the bearings at each end of the shaft get gummed up and or corroded and then bind. see this link from Audi fans ...................

[V8] Sticking throttle Q

"It's not the throttle body that sticks, it's the throttle shaft. And yes you
have to remove the intake to get to it.
The good part is that the bearings are available from a bearing company for
a few bucks each..."

I'm trying to search for a thread that had the bearing part numbers and where you could get them, NOT from Audi.

It's possible that if the intake is removed to gain complete access to the shaft the bearings could be cleaned and re-lubed and you might be just fine.

V8BOB

Found an old post that will give you some insite, it's from 2005. https://www.audiworld.com/forums/aud...start-2193891/

The directory is getting quite large now. I've still got to tackle these. The weather this week is going to be terrible though. Drizzle, followed by light rain and more drizzle. Morning fog will be followed by drizzle and more light rain. Much the same for the next day but with a shance of heavy showers... sounds like Britain! Here she be:

A week or so ago I posted about a sticking throttle linkage but did not get much in terms of accumulated group experience. Here's what I found out:

The throttle linkage (P/N 077-133-087A, price about Can$1,000) installed inside the IM consists of a long shaft and a bracket. The bracket is attached to the back of the engine under the airbox by two 10 mm nuts. The front end of the shaft sits in a "mounting" (P/N 077-723-319G, price Can.$523.00). The mounting is held by a single Allen head bolt.

In my case, the shaft was sticking and not returning to rest position, not engaging the TPS and causing very high idle. I removed the two bolts holding the bracket but could not take the shaft out because it was hitting the water pipes at the rear of the engine. All I could do is lubricate the bushing and get it to move freely again.

The real trouble was at the front. The mounting, accessible by removing the ISV and throttle plate assembly, is a small alloy casting with a bearing pressed in. The bearing was seized solid.

I managed to get an identical sealed bearing, part #698ZZMC3E made by NSK Bearings, for $25.

( GOOGLE Part# and get this https://www.motionindustries.com/pro...p?sku=00123085 )

With butterflies in my stomach I proceeded to press out the old bearing from the mounting, remembering the dealer price of $523. Well, after a few days of soaking in diesel fuel it came out without any trouble. Only the inner race is accessible from the back but apparently the bearing's construction is such that you can press the whole thing out just by pushing on the inner race. I used a vise, no need for a hydraulic press. I pressed in the new bearing and voila - the throttle linkage is moving again.

I have not been able to take out the shaft with its bracket but suspect the same or similar bearing is used at the back of the engine as well. It's very difficult to see given very tight space. Perhaps someone with the engine out of the car could check that.

Follow up:

The rear of the shaft passes through a small bushing, there is no bearing at all


__________________
Cheers;

Boxerfan

paulpas

Thanks for all your hard work. I remember seeing some how-to on throttle body maintenance, with pictures, and haven't been able to find it again. I'll look further and report back.

paulpas

Removal, cleaning and replacement of PT V8 throttle body - Knowledgebase

There we go. I'll have to have my mechanic read this before he dives into it in his heated garage. I'm exposed to the open air and it's too cold to work on the car up here in SE Wisconsin.

paulpas

I'm confused when it says "There is a mounting allen bolt (straight arrow) which needs to be removed to release the bracket, but it seems like it can’t be removed without pulling the whole manifold off."

According to the diagrams that's not necessary. It's corroded on so I'll see if I can break it loose.