rmcoasby

- similar post also on IWOC -

All,

I have a more or less standard STiV, the only mods being scoobysport exhaust/downpipe, (which has been on a year) and, as of last week, a green cotton panel air filter.Wednesday night everything went pear-shaped. As I was on my way home up a long incline, doing around 160KM in 5th I began to notice a loss of power and the car ground to ahalt. The car was picked up and sent to my garage. A leakage test was done and it appears I have melted a piston or two. By the way, a leakage test was coincidentally done 4 weeks ago and I had a good result - 2% in each cylinder. I am now facing an engine re-build which surprises me as I have always been careful. I have had the car from new, always serviced it correctly, I use 98 RON fuel, (I live in Cyprus...we get 98RON here) and rarely go over 6500-7000RPM.

It appears at this stage to be a faulty MAF sensor. After reading through some posts on here I noticed a few with similar problems. Any tips on avoiding in future once I get the engine back? I understand now a knocklink is more or less essential. Some mentioned an aftermarket ECU as a good idea and some an air/fuel ratio meter.

Any help appreciated

Richard

Andy McCord

re-map IMHO is the way to go, knocklink & lambdalink for peace off mind, have a read here john banks I hope there are some ECU mappers nearby to where you are, john will also do a postal map 4 you (AKA Tek 2.5)

StickyMicky

a remap is nothing tho if the maf sensor breaks?

far better to have sum kind of indicationof the sensor failing likea a/f guage or simmiler

sg72

My STI V Type R Blew up big style IMO. due to a faulty MAF.

Just recently got car back. Will be fitting a SECS. unit.
This plugs into your ECU port and can display readings from the MAF sensor (Amongst other things,Lambda/knockcorrection/Boost.......and more
Also have Knocklink and Oil press/Temp Gauge.

Yes ...and spare MAF sensor...Lucky white heather,Rabbits foot....

dowser

Was the panel filter an oiled one? Sounds like MAF may have been contaminated leading to leaner AFR's.

Richard

john banks

I don't do postal maps for STis or P1s. It is just too risky. Needs to be custom mapped.

There are things you can do yourself to monitor/sort it.

For example:

Delta Dash allows you to retard up to 5 degrees across the range
Knocklink will pick up detonation
Adjustable restrictor valve to control boost spikes with decat
HKS AFR would allow you to increase the MAF readings slightly which would richen the mixture and retard the timing slightly
Octane booster
FMIC
Water injection

Any or all of these things could be used to make it safer without getting it remapped and they are all within the realm of DIY with enough research into them first and a systematic careful approach.

john banks

Aftermarket ECUs can get rid of the MAF sensor which is arguably a very good thing on these cars. However, your problem will be getting someone to tune it for you.

If you every STi had a knocklink and a boost gauge, a lot of engines would be saved IMHO. You would get some warning of a MAF problem. The first flick to red of a well positioned knocklink will give you plenty of time to back off, investigate and avoid disaster. If everything is fine you'll just see a bit of flickering of the first few lights at high RPM most of the time.

rmcoasby

Thanks for the responses. I'm still waiting for news on the block which appears to have damage also. Looks like it will be a very expensive month.

Local chappy is recommending an exhaust gas temperature sensor. Any thoughts on that?

Can't believe that I was contemplating 1500 quid suspension upgrades only a few weeks ago and now I will have to spend more than twice that to get the bloody mule back on the road as it was. Very, very depressing.

Richard
Limassol, Cyprus

Leslie

Frightening to think that much damage can occur so quickly. Hope it is not too bad when you get it apart.

Les

rmcoasby

Les, I know - it's amazing. 4 weeks ago I had a leakage test done during the 50,000KM service. 2% in each cylinder which I understand is excellent. Now the thing is in pieces, seemingly due to a 74 quid sensor. Waiting for the call from machine shop on whether the block can be salvaged.
Cheers, Richard