RPM Drops Suddenly on S80 2002

[umarpaf]

Guys i recently purchased Volvo S80 2002 and coupla days later i started having this problem.

Problem Statement
=================
The engine start perfectly and smoothly. It becomes stable at 800. But after driving quarter of a mile it suddenly drops to 200 - 300 range momentarily. On most occaision it picks itself up to 1500 - 2000 Range. But on some occaisions it stops working and battery lights come on. During the RPM drop there is a complete power loss and car looses speed very quickly.

Needless to say its very hazardous in high traffic + high speeds.

Initial Diagnosis & Repair
=====================
I took it to Volvo dealership here in Riyadh and those guys took it in for two days. At the end of that period they said it was an O2 sensor issue and they have cleaned it and reinstalled it. So now everything is OK. I paid them and took the car to the road. But after travelling a coupla miles the problem returned.

So i took the vehicle back to them. This time they kept it for 5 days and at the end of it they said the Throttle module (ETM) is faulty and needs to be replaced at a cost of 7000 Riyals ($1850 apporox). I could have gone for that but when I asked them if they gurantee it that after this fix the car would run okay? They were shaky on that.

So i then took car to an old volvo mechanic who was supposed to be a guru (he served at volvo for 18 years and now operates his own volvo workshop). He did the following troubleshooting :-

(a) Checked Plugs and Coils , replaced one coil
(b) Checked + cleaned Filer, air intake
(c) Replaced ETM with five different used (but serviceable) ETM units of the same number. Without success.
(d) Reconnected a hose towards the radiator side which he says was lying unconnected
(e) Checked serveral times with small handheld device called 'computer' and found no error code or message.

Finally
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Now this 'guru' has come to the end of his line and says he cant do anything more. Please help me as i am now getting desperate and disillusioned with this car. Should i go for a engine change ... or you think its not worth it ? Should i salvage it for scrap ???

[vegasjetskier]

Read the forum "Don's ETM Room." You might want to go for the XeModex ETM repair @ about $600. You can't just drop any old ETM into the car - it has to be "married" with a computer. I hope you still have the original ETM.

[jbrown122]

On the 2002, I believe the S80 has an ETA. Not an ETM. And they don't normally go.