1999 BH5 TT Wagon : almost no boost in first gear even up to 6k revs??

[dumbskate]

I guys,

I bought new wagon just before Christmas and coming from an Gen II Auto everything thing seemed fine as far as power went. Once the new shine wore I started feeling (with the bum dyno) that first gear had no real oomph when driving around town.

Today I hooed up a cheap "Auto Gauge" boost gauge and it seems to do the following from stand still (idle)

1st gear: needle jumps straight from -20 to 0 but then pretty much just sits there until gear change at 5k

2nd gear: boost gets up to about 6psi and if I keep on the gas I can get about 9psi before heading for 3rd gear

3rd gear: about the same as 2nd really.

It really just feels like the primary is getting no pressure in first gear.

I am not to concerned about fixing this myself unless there are few basic tips like check particular (numbered) vacuum hoses, etc. More importantly I woudl like your opinion on whats up before I hit a Subaru specialist. Also if any of your guys think you can fix this and you have a workshop in Auckland (closure to the city the better) then pipe up or PM me.

[Joker]

Myth was that 2ndry was t activated in 1st but more than one of us can confirm it does - sorry cant help much other than that we snippet

[Carbon]

Certainly check all the vacuum lines, follow each one to ensure its not pinched or disconnected. Especially the T piece near the BOV

[dumbskate]

 JoKer said:

Myth was that 2ndry was t activated in 1st but more than one of us can confirm it does - sorry cant help much other than that we snippet

Hey that is useful as this could mean the primary is not giving any boost at all.

[log1call]

Was this test up a steep bit of road, or with a car full of mates to put some load on it?

I wouldn't expect to see any boost in first gear really, well bugger all anyway, there wouldn't be time would there?

[ReubenH]

I got pleeeaaanty of boost in first with my GTB (bout 12-14psi), and it kicked into secondary around 6000 RPM (when in first gear, would be at 4K on the other gears, and around 16-17 psi).

I'm thinking it could be a tired old primary turbo, but there's so many other things it could be too. I'd take the intercooler off to see if there's excessive oil coming out of it or somethign like that (a little oil is to be expected btw).

You're doing the test at full throttle right?

[zarnah]

 

I woudl like your opinion on whats up before I hit a Subaru specialist

hope it doesnt come to that........lol

[dumbskate]

 ReubenH said:

I got pleeeaaanty of boost in first with my GTB (bout 12-14psi), and it kicked into secondary around 6000 RPM (when in first gear, would be at 4K on the other gears, and around 16-17 psi).

I'm thinking it could be a tired old primary turbo, but there's so many other things it could be too. I'd take the intercooler off to see if there's excessive oil coming out of it or something like that (a little oil is to be expected btw).

You're doing the test at full throttle right?

Yeah I at least got the factory amount from my old Second Gen TT but this doesn't seem to be the case here. How did you get on having the boost turned up that high ? I figure with the weekend here I will hook up the boost gauge again (I only got one for this testing so it gets temporarily tapped to the hood) and do a bit more fiddling about. I hope this will give me some answer but I know my Subaru so it will probably just cause more questions.

[ReubenH]

I have no idea why it was boosting so well, there were certainly no modifications to the system. It's a 98 BG GTB Limited. Might be special Might be why it blew a big end...

[log1call]

Ha, it may not have been the boost that blew the big-end.... perhaps it was first gear that did it.

If I needed to have full boost in first... I'd just start off in second!

Kidding! Kidding!

[dumbskate]

Bad Auckland weather and no garage means no looking under the hood till tomorrow.

As an aside; Could someone let me know what sort of boost I should be seeing through the first few gears and rev range so I can get a bench mark for my tinkering.

[KwS]

check all the intake piping and vacuum pipes. My old TT liked to randomly spring a leak on the turbo outlet pipes. turned out to be lose hose clamps.

[dumbskate]

 KwS said:

check all the intake piping and vacuum pipes. My old TT liked to randomly spring a leak on the turbo outlet pipes. turned out to be lose hose clamps.

Yeah thanks. Just waiting for the rain to stop now.

[dumbskate]

Just an update: I gave everything a good check over and tighten all the hose clamps, crimps, etc regarding the primary and now the boost is a nice constant. Thanks everyone for there help with this.

[Hailz]

Hey it might be a coincidence but I have noticed that my BG5 wont get any 2nd turbo and bugga all boost in first if I have next to no gas in the tank eg on fuel light - might be something to consider.

[ReubenH]

 Hailz said:

Hey it might be a coincidence but I have noticed that my BG5 wont get any 2nd turbo and bugga all boost in first if I have next to no gas in the tank eg on fuel light - might be something to consider.

Maybe fuel surge?

[dumbskate]

For me I woudl most likely say it was a poorly tightened hose clamp between the intercooler and the throttle body.