Fixing the overboost issues with the MN 2.5HP

[jamesb_bau]

thanks for your assistance all, so far..its appreciated and i know some of your time is valuable

Somemore testing has taken place, as follows...

Disconnected Dawes and ramp up,
checked dawes valve with some special sucking menthod (yep u know the one) and it holds vaccuum nicely.
Reinstated boost soleniod + L/R mod 1 (one-way valve),
Took for a freeway run up same bit of raod that showed CEL's previously .... All fine...
Even gave her a good hit of pedal after backing off (if u understand) to see what she would do-----
All good again, zero CEL and she may have seen $1.40...

I could be mistaken, but if feels to pull under boost better and possibly spool up nicer...

I'm hoping its not the dawes as i like this added safety feature..

since putting blank in with L/R mod, and before dawes install, i never saw a code (even before software update).

getting closer..

thanks again

Rob

[Howie763]

Gday all,

I have just got my MN manual back from a "soft ware" update to rectify a problem with P1299 VGT system. Went into limp mode pulling up a sttep hill on the way to Sydney. I pulled over and rand my dealer who said leave it for 5 minutes, restart it and see if you have full power. Did this and all was good for about 20 minutes. Hit the next long steep hillm and off it went again. Pulled over and onto a flat top she went.
Mind you it was a very hot afternooon.

Three weeks later and headed north, long steepish hill, much cooler weather and it appears I have the same problem. All synptoms are the same. I didnt fancy being stuck on the side of the road Christams eve, so I rang the dealer again. Told restart it and see... No problems, full power and all seems okm escept the engine light is still on. Just before it went into limp mode there was a strange noise like air being blown off at high pressue. I actually thought it was a siren.

Just a last bit of information, at the last service a new inlet manifold and turbo sensor were fitted. As i had no problem with this before, could this be part of the problem?

Any input would be appreciated.

[Cowboy Dave]

Why is this post in the ECU learning thread?

I reckon you need to read this thread:
http://www.newtriton.net/phpbb/viewtopic.php?t=12233#p289680

Are you running an EGR blank or oversized exhaust?

[Howie763]

I have added to my post, please see below.

[Howie763]

Thanks Cowboy.

I have copied and pasted my post into that thread. I posted here as I did a search for the P1299 fault and this thread came up.

No I am not running either.

Thanks,
Phil

[Howie763]

Gday all,

I have just got my MN manual back from a "soft ware" update to rectify a problem with P1299 VGT system. Went into limp mode pulling up a sttep hill on the way to Sydney. I pulled over and rand my dealer who said leave it for 5 minutes, restart it and see if you have full power. Did this and all was good for about 20 minutes. Hit the next long steep hillm and off it went again. Pulled over and onto a flat top she went.
Mind you it was a very hot afternooon.

Three weeks later and headed north, long steepish hill, much cooler weather and it appears I have the same problem. All synptoms are the same. I didnt fancy being stuck on the side of the road Christams eve, so I rang the dealer again. Told restart it and see... No problems, full power and all seems okm escept the engine light is still on. Just before it went into limp mode there was a strange noise like air being blown off at high pressue. I actually thought it was a siren.

Just a last bit of information, at the last service a new inlet manifold and turbo sensor were fitted. As i had no problem with this before, could this be part of the problem? I am not running a big bore exhaust, egr blank or a chip.

From reading here it appears mine is a low pressure issue not overboosting. I gather the Dawes valve application would not be relevant to my issue??

Any input would be appreciated.

[NowForThe5th]

Posts moved. To keep it tidy.

[biggibbo]

Gday all,

I have just got my MN manual back from a "soft ware" update to rectify a problem with P1299 VGT system. Went into limp mode pulling up a sttep hill on the way to Sydney. I pulled over and rand my dealer who said leave it for 5 minutes, restart it and see if you have full power. Did this and all was good for about 20 minutes. Hit the next long steep hillm and off it went again. Pulled over and onto a flat top she went.
Mind you it was a very hot afternooon.

Three weeks later and headed north, long steepish hill, much cooler weather and it appears I have the same problem. All synptoms are the same. I didnt fancy being stuck on the side of the road Christams eve, so I rang the dealer again. Told restart it and see... No problems, full power and all seems okm escept the engine light is still on. Just before it went into limp mode there was a strange noise like air being blown off at high pressue. I actually thought it was a siren.

Just a last bit of information, at the last service a new inlet manifold and turbo sensor were fitted. As i had no problem with this before, could this be part of the problem? I am not running a big bore exhaust, egr blank or a chip.

From reading here it appears mine is a low pressure issue not overboosting. I gather the Dawes valve application would not be relevant to my issue??

Any input would be appreciated.

i would say your latest problem from ur description is the turbo to intercooler hose has split or worked loose.

Makes a noise just like you described when it let's go and also throws the 1299 code- no boost

[Shwa]

How did you go Howie? Did you get your issue resolved? I ask because I had a similar issue the other day, intercooler inlet hose blew out (split). Made a bit of a bang then a loud sucking noise. I replaced the hose and later that night it blew off the intercooler. The second may have been my fault if I didn't tighten the hose clamp properly. I've since replaced the hose clamp and have been watching the boost on the scan gauge like a hawk and only seen a spike up to 21psi so far before it dropped back down to about 12. I am running a 3" exhaust and egr blanks but just interested in other causes as neither of these mods is new.

[Howie763]

Gday Shwa. Thank you for your interest. I have had the vehicle back to the dealer a few times. I looks like they have finally fixed it. They replaced the turbo sensor and replaced some of the vacuum hoses.

It has also restored some of the bottom end that went missing when the last "overheat" update was done. All round the beast seems to be back to probably a tad better than pre limp mode days.

[Shwa]

Glad to hear Howie. I'll keep my eye on my boost for any further spikes. Unfortunately I'm just out of warranty now anyway.

[alian]

From What I have been reading bolting on a 3" system enhances the chance of this happening ??

[spoiltone]

Yeah when I fitted a 3" it happens near straight away. I also had a chip. And even over heated one day. So I sold the chip and exhaust. Bad mistake I had the best fuel economy I ever seen with the chip and exhaust. In place. Just over heated and over boost limp modes.

[Jrosey]

I have had the 3 inch exhaust and a Chip-it chip for in for about 12 months and no issues . Exhaust temps improved slightly (lower) with exhaust. Still a bit high I feel but can't do much about it. I also have the EGR electrickey in place from Tony. Might need to chase a Dawes valve if problems occur. Hope everything operates as it's supposed to as we are off to the high country for 8 days in the middle of the month.

[Shwa]

[quote="Jrosey"]. I also have the EGR electrickey in place from Tony.quote]

Hmmmm... What is this electrickery with the EGR you speak of? Does this prevent limp modes from the EGR blanking?

[Cowboy Dave]

Yes. It replaces the blank and tells the ecu that EGR is not required by interfering with a temperature sensor signal.

[headlights]

G'day
We've had a couple of nasty experiences (almost ended up as bonnet ornaments on B double's!) with the engine cutting out completely on our 2010 MN auto dual cab 4WD while under acceleration towing a camper trailer (1.6t). The engine restarted OK and we had an engine check light. This was checked by a mechanic in the next town who said it was a "turbo overboost" code. I can't reproduce the effect when the trailer is not attached.
The dealer/company (as expected), won't have a bar of it even though there's still a month left on the 5 year warranty. The reason being that I have had the temerity to add after market parts to the vehicle.

The ute has a "Sprint Booster" added to the throttle, a Unifilter air cleaner, snorkel and a 3" s/steel exhaust. Other than that the "power plant" is standard.

My mechanic has spent 2 days on it and can't come up with an answer as to why the vehilce dies when under load and towing. He has suggested replacing the "turbo solenoid (?) and removing the sprint booster, and if that doesn't work, fitting an new ECU!!$$$

Does the collective knowledge and expertise out there have any ideas on what the problem may be?
Thanks for your time in reading this post. Cheers Lou

[Speedy70]

Try this link.

viewtopic.php?f=23&t=12233&p=390551&hilit=over+boost+on+hills#p304490

[mattz]

It's a common problem with the mn and a 3in exhaust.
If you do a search on "overboost" or "Dawes valve" you'll find plenty of info.

[Cowboy Dave]

And in this case the dealer is partly right since the exhaust is the most common cause of the problem. Some do it without but not many compared to cars with 3 inch exhausts

[snowman]

My mechanic has spent 2 days on it and can't come up with an answer as to why the vehilce dies when under load and towing. He has suggested replacing the "turbo solenoid (?) and removing the sprint booster, and if that doesn't work, fitting an new ECU!!$$$

Does the collective knowledge and expertise out there have any ideas on what the problem may be?
Thanks for your time in reading this post. Cheers Lou

yes it is solvable and depend on how you want to go about it.

All the info is here . and yes you will need to do some reading.

[coughy]

Get the latest ecu update i feel as mine is fix if not all gone and is much better now after it...
Then fit a dawes valve easy to do get it from spv industrys tony on here and all will be great

[hvac guy]

U could a get a bit of exhaust pipe and make a 3 to 2 1/4 tip that u can clamp onto the exhaust tip while towing to help stop the over boost

[Hugebettyswollocks]

Hey Guys, need some help and not having much luck searching, Iam wondering if my problems are to do with over-boost?

My 2012MN manual triton has no engine or exhaust mods, done 53K. Last week on a short trip, had cruise control sitting at 100kph start going up a small hill and the engine starts to falter, as if it was cutting in and out. I take off the cruise control and it still does it. So l pull over and the engine is running fine, l pull off again and get away no problem in 1st and 2nd , but cant get past 2500rmp in 3rd and have to change up. It appears that in the higher gears when there is demand on the turbo it doesn't work right and the revs seem to be limited. Also changing between gears when driving normally there appears to be a small amount of over-revving once accelerator is lifted and clutch pressed in.

As luck would have it l had the car booked into the dealer as synchromesh going in to 3rd is gone, and they were going to look at it. I tell them about my problem too.

So pick the car up today and they have ordered the gearbox parts, changed the coolant as part of a recall that l missed and tell me the turbo is working fine. They said that because l use a K&N filter, it covers the MAF sensor in oil and can cause the problem, they advised to replace with original. I told him l clean it every month as l do and it got cleaned yesterday. He then said that maybe the oil has blocked the intercooler causing insufficient boost pressure. So l drive home with exactly the same problem l started with.

I have not had a dealer service in the last 2 years, so only had one ecu update back in 2013. However they did re-flash the ecu today for the coolant recall.

Any ideas, or can you point me in the right direction?

Thanks

[Cowboy Dave]

It doesn't really sound like over boost to me. Nor the MAF sensor despite what the dealer bloke said. The slight rev on clutching in is a common complaint and apparently by design. I'd be surprised if it was oil in the intercooler too, sounds like random excuses really.

The rest I'm not too sure on. Maybe check your turbo hoses? How long since you changed the fuel filter?