Welcome to the North American Subaru Impreza Owners Club Thursday March 28, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L Turbo)

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 06-13-2017, 11:01 PM   #1
D3LTAwrx
Scooby Newbie
 
Member#: 446267
Join Date: May 2016
Chapter/Region: TXIC
Location: Dallas, TX
Vehicle:
2014 WRX Premium
Dark Grey Metallic

Exclamation Coolant Overflow Mystery! But It's Not The Head Gasket?

Okay so here is the problem:
- When driving hard and under heavy boost such as at autocross or at the track, coolant pushes into the overflow tank to the point where it sprays out of the top and into the engine bay.

Here are details about my WRX:
- 2014 WRX Premium Sedan
- 41k Miles on odometer
- 325whp/385wtq on E75 @ 20 PSI
- Tuned to above levels since 02/2017

Here are the modifications:
- Full Catted TBE
- Cobb Intake
- Cobb Flex Fuel Kit
- Cobb FMIC
- 1000cc ID Injectors
- AEM 320lph Pump
- IAG AOS
- Koyo Aluminum Radiator

I'll just jump to when the problem first started...
I DIY installed the flex fuel, fmic, and pump from the list above and then got tuned shortly after by Calvin of Dotson Tuning on AWDTunings Dyno. The car did really well and put down 325whp no problem.

The following weekend, I take my car to autocross and start doing runs. After the first session I popped the hood and noticed coolant in the engine bay that had clearly come from a full to the brim overflow tank that was bubbling. No signs of oil, it just looke like clean coolant with big air bubbles. I dismissed it at the time and ran the rest of the day with no overheating. I even drove back on the highway for an hour.

So fast forward a month later with coolant issues but some gaskets in the fuel pump came loose and i had to fix it and get retuned. I got that done and all was well again. A week into my retune I finally push the car hard and the my coolant overflows again. I do some research and start suspecting the head gasket.

Fast forward to now. At this point I can recreate the issue by doing a 4-5 consecutive hard pulls. I feel like I have tested everything I can to see if it is indeed the head gasket and all tests are telling me it is not the head gasket...

Here is what I have tried to do to fix the problem in order:
1. Burped the system with no spill funnel. I do this many times.
2. I replaced both radiator caps with Radium 1.5 bar caps as suggested by AWDTuning. Problem persisted.
3. Inspected coolant lines by thermostat housing, turbo, and radiator. No leaks.
4. Took off undertray for a few days to see if coolant leaked onto the ground. Nothing.
5. Observed coolant levels for a few days and none was lost.
6. Had radiator pressure tested. No leaks.
7. Replaced stock radiator with aluminum Koyo radiator. Problem persisted
8. Switched back to stock radiator caps. Same issue.
9. Brought it to Growler Motorlabs (formerly Cobb Plano). The techs did a chemical combustion gas test which turned up negative. I brought it back on pump gas only as advised and they tested it again. Tests were negative for HG failure.
10. I spoke with Cobb techs and they say it doesn't seem like a head gasket issue. They seemed to not be able to come to a definite conclusion which surprised me.

During this time my coolant temperature never went over 210F!

I also never noticed the typical head gasket signs such as milkshake like residue in oil. I am not losing coolant, it just keeps overflowing. I've heard that a crack in the turbo can cause this but am not sure about that. The car runs fine and doesn't overheat. Im stumped therefore I call upon the mighty power of NASIOC to help me decide...

Do I need a head gasket job or new turbo? Am I insane? Am I going insane? Help!
D3LTAwrx is offline   Reply With Quote
 

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 01:07 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.