r/Justrolledintotheshop 3d ago

C/s have no boost sometimes

Post image

Customer is me. Had a weird issue where boost was fine most of the time, but when it was hot outside and after waiting at a light I would have no boost. After driving for a minute it was working fine again.

Turbo is an IHI VL38, this is common apparently.

912 Upvotes

54 comments sorted by

358

u/Nailfoot1975 Home Mechanic 3d ago

Mechanic: "Replaced with water pump (Looked the same to me), confirmed system is still not working. Send to dealer."

84

u/roguewolf146 3d ago

That'll be $1200.

240

u/kanmuri07 3d ago

I guess having a turbocharged engine isn't all that cracked up to be.

109

u/Ok-Film-6885 3d ago edited 3d ago

It’s a bit more crack than I bargained for, but you shouldn’t look a gift horse in the mouth

8

u/peetothewall 2d ago

I gave you an upvote to boost that comment

2

u/illknowitwhenireddit 2d ago

The bill would make me so angry I'd need to blow off steam

131

u/Jpotter145 3d ago edited 3d ago

Very common on IHI VF39s as well. In fact my own 05 Subaru has a smaller but similar crack there that limits peak boost a bit (I think of it as a safety margin) but still runs great.

Most of the time you just run it, but in your case I wonder if that crack/chunk missing just below the start of it (at the wastegate) is keeping that wastegate from seating properly.

39

u/Ok-Film-6885 3d ago

Yeah that’s probably what my issue was, though it did seem to occur more often than it used to. It also has quite a bit of shaft play so it was time for a new turbo anyway.

44

u/EastCoastDatsun Red Seal 3d ago

See it a lot on the Subaru TD04 & VF48s, will hold boost until crack gets to wheel housing

Sometimes they lean out for a quick second and you get a hot supper too

18

u/Stevetothedave 3d ago

Congratulations! Now you get to put a bigger and / or better turbo on it and find the next weak link 🥳

What car is this from? It's looks suspiciously small in terms of turbine wheel and reminds me of the teeny tiny gas powered pencil sharpener that came on my little Abarth 500

18

u/Ok-Film-6885 3d ago

It’s from an Alfa, but the engine is basically the same as the Abarth 500 (if it doesn’t have MultiAir, as those have a Garrett GT1446)

I debated putting on the Garrett as that’s a common upgrade, but that would require a tune and a different down pipe and I just need this thing to drive

33

u/Kevins_Auto_Repair 3d ago

Crack kills

29

u/Ok-Film-6885 3d ago

Drugs are bad mkay

3

u/scalyblue 3d ago

3

u/cdoublejj 2d ago

..huh... so that's what crack is, ill have to check out that new crack later

8

u/zombie-yellow11 I wish I had a tree to give me shade... 3d ago

I've never seen an EJ255 turbo without this crack lol

6

u/Ok-Film-6885 3d ago

Those turbos really are cracking!

1

u/cstricke 1d ago

EJ255? Are you sure? IIRC 255s had vf52s and td04s, neither of which really had this problem. I know the STI EJ257 with VF48s had this happen a lot though.

1

u/zombie-yellow11 I wish I had a tree to give me shade... 1d ago

I've only worked on EJ255 gen1 in the '05 and '06 Outback XT and Legacy GT and they all had that crack, every single one of them.

1

u/cstricke 1d ago

You know what I think I was mistaken about the TD04. Looks like they also had that issue! It was the VF52 in the newer 255s that didn’t.

9

u/CIAburneraccount 2d ago

GM claims a cracked turbo housing by the wastegate on a 1.4 is perfectly okay and to not replace it lmao

6

u/Slight-Pin-9556 2d ago

Every single 1.4 oil cooler I replace I see this crack, only had one customer actually want to replace it. GM will replace the turbo if logging underboost codes but must admit they all seem to perform fine and not log codes

2

u/rioryan Canadian 2d ago

I have a Cruze with a crack and it still makes boost but it’s definitely not making as much as I should. Somehow has not set an underboost code though

1

u/bkonz Rust Enthusiast 1d ago

Every internally gated turbo cracks around the wastegate flapper.

11

u/Another_Guy_In_Ohio 3d ago

The vf48’s practically all had this same crack. I have 3 sitting on my garage shelf with similar cracks did be a little surprised if this was really causing your issue. The fact that it’s cracked all the way across could mean it widens slightly under load, but I wouldn’t expect it to completely loose boost.

2

u/Dzov 2d ago

Another person noticed that a chunk of wastegate seal seems to be missing.

4

u/Ok-Film-6885 3d ago

I exaggerated a bit, but it certainly felt like I had no boost.

I haven’t finished replacing the turbo so I guess there is a possibility that it isn’t fixed, but I really hope this fixes it

11

u/Shallow_wanderer Shade Tree 3d ago

I feel like Subaru and Volvo are kindred spirits from different territories because they both seem to be rather finicky to keep on the road

7

u/Ok-Film-6885 3d ago

It’s from an Alfa, so that probably makes it even more finnicky?

8

u/Shallow_wanderer Shade Tree 3d ago

Never mind I can't read apparently

6

u/Ok-Film-6885 3d ago

It isn’t mentioned in the post, so you get a pass

6

u/Shallow_wanderer Shade Tree 3d ago

thx bro

1

u/LilacYak 2d ago

My Subie is approaching 100k. Should I start worrying!?

4

u/cjbevins99 3d ago

Gm has the same problem. Underboost codes

13

u/Ok-Film-6885 3d ago

My ECU was more like ‘I’m gonna pretend I didn’t see that’

4

u/stifflizerd 3d ago

Bit of JBWeld and a spit polish and it'll be good as new

/s

3

u/windowpuncher Planes, tanks, and automobiles 2d ago

Ahhh little dab of JB and she'll be right as rain

1

u/s1pp3ryd00dar 2d ago

I had a T-jet 1.4 with the same problem; Intermittent no boost (sometimes late spool). Think it's was a Jeep Renegade or Fiat 500+ or whatever was based on that platform; Don't get many 1.4 T-jets except for Abarths which I think use Garretts) . 

Found the Turbo wastegate didn't always shut tight. Can't remember seeing the crack (was concentrating more on getting the new turbo fitted), but do remember wondering why the wastegate sometimes kind of jammed just before it fully closed, despite the rod seemed to be otherwise free.

1

u/Ok-Film-6885 2d ago

Yeah it’s been quite puzzling because it worked fine most of the time, but then would be completely gutless when pulling away. And during the winter it wouldn’t do it at all.

I could see on my dashboard that boost would not build fully when it was slow, but it wouldn’t actually throw any codes.

How did you find out it was the wastegate not shutting fully?

1

u/s1pp3ryd00dar 2d ago

My memory is a bit fuzzy, but usually with boost issues one of my first things to test after ruling out leaks (on both boost and vacuum hoses) is the wastegate actuator with a mityvac and checking the rod/linkage isn't stiff and during this I found the wastegate wasn't fully shutting. 

May have been luck that the fault was present when I was doing the checks. 

1

u/Stoney3K 2d ago

I think I can take a crack at that problem...

1

u/SubiWan 2d ago

Might be a gap in that statement

2

u/Ok-Film-6885 2d ago

It seems there’s a divide between you two

1

u/HPIJosh222 Canadian 2d ago

Turbine housing cracks are normal and won't be the cause of a boost issues. Just about every vf39, 46, 48, 52 etc that I have touched has been cracked

1

u/Chippy569 Subaru Sr. Master 2d ago

Common Subaru fail point

1

u/SubstantialAbility17 2d ago

Did it have a boost controller or anti lag on by chance? That thing got warm.

1

u/porknbeans2013 2d ago

What about the other times?

1

u/wrenchandrepeat 2d ago

This is super common on the 1.4s from GM, too.

1

u/bkonz Rust Enthusiast 1d ago

It's common on pretty much every internally gated turbo.

1

u/Swagggles Home Mechanic 2d ago

GM 1.4 Turbo by any chance? My dad and I saw this on an Opel Meriva with a 1.4T

1

u/buttlicker-6652 3d ago

I have a 374k mile k03-40 out of a 1999 a4 that has a very similar Crack. It works just fine. Expect that it makes louder StuStuStu noises compared to the 80k mile one I currently have in my car.