Jump to content
SAU Community

Recommended Posts

Currently having some boost issues, what seems to be happening is on light boost the gauge seems to be waving so if I am driving along and take my foot off the pedal and try and level out the boost to say sit at 3700 the gauge will not sit at say 0.5 bar it will surge from say 0.3-0.5 like the boost gauge is waving at me. You can hear the BOV hiss and close and hiss and close. The turbos recently got replaced with steel wheel items , and boost seems to build alot slower than what it used to considering they are pretty much stock but steel wheel. when I changed the turbos also changed the wastegates as they came with the turbos. running stock boost controller as well. Full boost by maybe 4k????

Now I believe my problem to be related to either

BOV leak

wategate problem

boost actuator

or slipt in one of the lines going to BOV, wategate or boost controler

What I was think about doing is pulling the hose off the boost controller and seeing if it will hold boost better and faster spool up (obviously not floor the car = unlimited boost)

Anyone help me??????

Link to comment
https://www.sau.com.au/forums/topic/268111-boost-fluctuates/
Share on other sites

Well disconected the acutator, and its still doing it its either a leaky BOV or the wategate opening?? anyone know any tests to check. I have a little compressor which I can run into the wastegates. How can I check to the BOV's????? it doesnt seem to be doing it whilst on full boost and will hold 14psi all the way(however it still could be leaking just cant tell) however its when building or maintaining boost it seems to fluctuate???

Hey guys I am still having this issue tonight I removed the air filter to see if intake pipe was sucking shut (its not) You can really hear the BOV leaking back into the engine I had a look at the hoses and they seem fine. When building boost it sounds like machine gun fire with the BOV venting back to the engine which makes me think it related to the BOV. If I have it in a tall gear and floor the car and boost will rise and fall and you can hear it getting vented, Now I would have thought if it were leaking from a hose to outside the engine then it will run rough and miss and splutter. So is it possible one of my BOV is stuffed and leaking????? The car will run full boost fine however.

Cheers

the BOVs are being fed from under the plenum there is a box type thing attached to the block, its fed the factory location I take it never had an issue with it before. It would have to be engine side of the butterflies. Spent this afternoon pulling the front bar off and BOV's changed the lines to going to the BOV's. cleaned the BOV's. pulled AFMs off and intake box checked all connections cant find anything.

the car has been blowing white smoke latley (oil) and can smell it, dont know if its related or if I overfilled the oil when I topped it up a few weeks ago, I am stumped????????? and getting frustrated.

What about a head gasket????? What else should I be looking for, I havent changed the BOV line going into the engine yet as its a bitch to get to however it seems ok.

Well cefiro, I have/had both of those problems. I currently have the fluttering boost... if i am at like 4 to 7 psi accelerator at 15% and the booster gauge bounces and there is noticable flutter when i boost and release. I current think that my actuator has died and i have been overboosting on occasions and it has lead to the stock BOV dying.. this leads to flutter but like u i have no idea how to test my theory

pulled both BOV off and both seemingly worked ok. could blow compressed air through to the BOV and see if they hold boost I think thats my next step to blow air through and see if there is a leak anywhere. Should have done this earlier. I only installed turbos in my car recently so I am not sure if its related. I should have a new boost controller on the way soo however I dont think its the issue as i have pulled the hose to the actuator off to see how it holds boost and it was still doing it.

Also just blocked the PCV valve and no love.....

Edited by cefiro

Sounds more like a leak to me.

Could be from one of the manifold gaskets... you said you just replaced the turbos - did you replace the manifold gaskets?

I would be looking for a split hose somewhere or your actuator has given it up, as you stated you can hold full boost it would be unlikely that you BOV's ar buggered...

White smoke is not oil - its water vapour - blue smoke is oil... you can check if you've overfilled it by simply looking at the dipstick marking... If it's too full just let some out via the sump plug and recheck the level.

My 2 cents.

tried blowing compessed air through the intake piping today took off AFM and blocked one and put pvc end with bike valve in it. Did find a small leak where the boost gauge is linked into, havent started the car yet however I dont think its going to be my magic bullet. Now if I run air through there should it pressurise the sump as I pulled the dipstick out air gushed out????

Any other options????? Ideas??????

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Surely somebody has one in VIC. Have you asked at any shops?  Is this the yearly inspection or did you get a canary?
    • This is where I share pain with you, @Duncan. The move to change so many cooling system pieces to plastic is a killer! Plastic end tanks and a few plastic hose flanges on my car's fail after so little time.  Curious about the need for a bigger rad, is that just for long sessions in the summer or because the car generally needs more cooling?
    • So, that is it! It is a pretty expensive process with the ATF costing 50-100 per 5 litres, and a mechanic will probably charge plenty because they don't want to do it. Still, considering how dirty my fluid was at 120,000klm I think it would be worth doing more like every 80,000 to keep the trans happy, they are very expensive to replace. The job is not that hard if you have the specialist tools so you can save a bit of money and do it yourself!
    • OK, onto filling. So I don't really have any pics, but will describe the process as best I can. The USDM workshop manual also covers it from TM-285 onwards. First, make sure the drain plug (17mm) is snug. Not too tight yet because it is coming off again. Note it does have a copper washer that you could replace or anneal (heat up with a blow torch) to seal nicely. Remove the fill plug, which has an inhex (I think it was 6mm but didn't check). Then, screw in the fill fitting, making sure it has a suitable o-ring (mine came without but I think it is meant to be supplied). It is important that you only screw it in hand tight. I didn't get a good pic of it, but the fill plug leads to a tube about 70mm long inside the transmission. This sets the factory level for fluid in the trans (above the join line for the pan!) and will take about 3l to fill. You then need to connect your fluid pump to the fitting via a hose, and pump in whatever amount of fluid you removed (maybe 3 litres, in my case 7 litres). If you put in more than 3l, it will spill out when you remove the fitting, so do quickly and with a drain pan underneath. Once you have pumped in the required amount of clean ATF, you start the engine and run it for 3 minutes to let the fluid circulate. Don't run it longer and if possible check the fluid temp is under 40oC (Ecutek shows Auto Trans Fluid temp now, or you could use an infrared temp gun on the bottom of the pan). The manual stresses the bit about fluid temperature because it expands when hot an might result in an underfil. So from here, the factory manual says to do the "spill and fill" again, and I did. That is, put an oil pan under the drain plug and undo it with a 17mm spanner, then watch your expensive fluid fall back out again, you should get about 3 litres.  Then, put the drain plug back in, pump 3 litres back in through the fill plug with the fitting and pump, disconnect the fill fitting and replace the fill plug, start the car and run for another 3 minutes (making sure the temp is still under 40oC). The manual then asks for a 3rd "spill and fill" just like above. I also did that and so had put 13l in by now.  This time they want you to keep the engine running and run the transmission through R and D (I hope the wheels are still off the ground!) for a while, and allow the trans temp to get to 40oC, then engine off. Finally, back under the car and undo the fill plug to let the overfill drain out; it will stop running when fluid is at the top of the levelling tube. According to the factory, that is job done! Post that, I reconnected the fill fitting and pumped in an extra 0.5l. AMS says 1.5l overfill is safe, but I started with less to see how it goes, I will add another 1.0 litres later if I'm still not happy with the hot shifts.
    • OK, so regardless of whether you did Step 1 - Spill Step 2 - Trans pan removal Step 3 - TCM removal we are on to the clean and refill. First, have a good look at the oil pan. While you might see dirty oil and some carbony build up (I did), what you don't want to see is any metal particles on the magnets, or sparkles in the oil (thankfully not). Give it all a good clean, particularly the magnets, and put the new gasket on if you have one (or, just cross your fingers) Replacement of the Valve body (if you removed it) is the "reverse of assembly". Thread the electrical socket back up through the trans case, hold the valve body up and put in the bolts you removed, with the correct lengths in the correct locations Torque for the bolts in 8Nm only so I hope you have that torque wrench handy (it feels really loose). Plug the output speed sensor back in and clip the wiring into the 2 clips, replace the spring clip on the TCM socket and plug it back into the car loom. For the pan, the workshop manual states the following order: Again, the torque is 8Nm only.
×
×
  • Create New...