Technical Turbo overboost light on dash

[DaleTDSX]

Hi guys

I have recently started running my 96 punto mk1 1.7TD after it being stood for over a year, everytime i got over 3k rpm in 3,4,5 gears the turbo overboost warning light comes on.

bearing in mind at this point i am doin under 60mph. Is this normal or any suggestions of the problem??

Any suggestions would be great

Thanks !!

 

[MadMan0]

my guess - having never worked on a fiat turbo system, is that the dump valve/release valve has seized or become blocked? If it has one, give it a clean and see if it still happens..

The only turbo system i've worked on was an M reg Mitsubshi 4x4 and even that was only when a hose broke. soz

I'll let someone with more exp give better advice

 

[DaveMcT]

Sounds like the turbo wastegate system is sticking - poppet valve or vanes depending on the model. Check the air pipe to the wastegate actuator and lubricate the linkage but the turbo may have to come off to do the job properly.

 

[DaleTDSX]

Thanks for the replies. Ill give that a look at and see wot happens. Just a bit unsure as never had a turbo before.

 

[DaveMcT]

To get enough boost at low(er) revs the turbo will be well able to blow the engine apart at high revs. So a bypass system is used to divert the exhaust gas. If it sticks shut the electronics protect the engine by cutting the fuel supply. Getting it fixed will improve performance and economy.

 

[DaleTDSX]

Hey guys. I kno its been a while for this reply. It was the turbo wastegate was seized slightly open so i managed to lube it up and free it off.

Getting the turbo off on the other hand was a horrible task. Everything is backwards on this car. The brackets are in places u just cant get to. Had to hacksaw the bolts off and then drill and taps them out to refit it.

But on the plus side its running really well now. So much more boost from te turbo and better fuel economy

Thanks for all the input though. Muchly appreciated

 

[MadMan0]

Result

 

[krypton]

I had a similar problem of P0238 error code on my 2006 1.9 JTD Doblo diesel. Let me share the process of diagnosis in case it helps someone.

First I removed the MAP sensor and saw it was caked with dirt and impossible to clean. I replaced it. Easy job as just one screw and a connector to remove. The car ran better but still low power especially going up hills.

Then I suspected a problem of stuck actuator rod on the waste gate of the Turbo. To check this I took off the bottom panel of the car and shone a light up on the actuator arm as my son revved the engine. No motion at all even after spraying some wd40 on the actuator arm. Then I removed the vaccum pipe to the waste gate actuator and discovered with my finger that there was no vaccum. I suspected a hole in the vaccum hose.

Finding the hole was not easy as the access to the vaccum hose is poor over a lot of its length and it feeds behind the engine where there is very little room. I unscrewed the mounting bracket of the fuel filter and pushed it to one side. I removed the pipe from the Exhaust Gas Recycling valve to the engine and cleaned it. Reaching below through the free space I was able to seize the vaccum hose and found the hole which I fixed temporarily with electricans tape. After putting back the EGR pipe I started the engine and this time the actuator arm moved and came back each time I took the vaccum pipe on and off it’s nipple on the actuator body.

Upon doing a test drive I found full power was restored and the car could drive up hills at speed with plenty of power.
Now I just need to buy a new vaccum hose and fit it next time I am working on the car…