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06-22-2018, 03:58 PM | #1 |
Scooby Newbie
Member#: 487504
Join Date: Jun 2018
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Tricky Diagnosis
Hi everyone,
I'm a first time poster with a tricky set of sign/symptoms that are making it challenging to diagnose a problem with my WRX, if it has one at all. First off, here are my car deets. It's a 2010 WRX sedan with no aftermarket mods except for one; I put in a Kartboy short throw shifter with bushings because the stock shifter was a crime against humanity. It just ticked over to 90k miles this morning and I meticulously maintain the car. I had the 90k service performed 1500 miles ago. Now onto the issues. I live in Seattle and was down in Portland two weeks ago. It was a cool 50° F very rainy day. On my way back during a refueling stop I noticed the temp gauge was almost in the danger zone. I checked the coolant levels, which were fine but the radiator was cold to the touch. While the car was under power, I noticed the temp gauge dropped back to normal levels. Maybe I've got a bad thermostat I thought. So I drove back to Seattle with normal temps. The moment I got off the freeway though, the temps started to spike again and the warm air from the heater HVAC vents suddenly became outside air temps. I drove it home, scheduled an appointment with the mechanic, and didn't drive the car for 4 days. The day I took the car to the mechanic I couldn't get the car to overheat despite my best efforts to do so. I let it get to normal operating temp and idled for 5 minutes. No change in temps. I drove up and down the road at 30 MPH in 1st gear/5k RPMs. No change in temps. I dropped it off at the mechanic anyway. He called saying he found oil in the coolant, which means it's the dreaded head gasket issue. I wasn't ready to perform the repair just yet and told him to hold off. He flushed the coolant and I picked up the car. He said the signs/symptoms were minor but present due to the oil in the coolant and compression tests. He said I could drive the car but with enough time, the problem will get worse. So I only drove the car for minor errands this week. I had zero abnormal engine temps. But I also scheduled an appointment for a second opinion at Rod's Japanese Auto in Bellingham. As far as I can tell they are the best at head gaskets in the Puget Sound region. They're so confident they offer a lifetime warranty on the repair. This morning I drove up to Bellingham. I was a bit conservative and kept my speed around 60 on the freeway in 5th gear. I wanted to keep the RPMs around 2500 RPM or lower. At 3000 RPM the turbo begins to spool. It was also quintessential PNW weather again today, with ~50° F temps and misting rain. Once again I had no abnormal engine temps. Rod's Auto Care performed a multi point inspection and couldn't find any sign/symptoms of a head gasket issue. They even poured the chemical in to identify exhaust in the coolant but got a negative result. The new coolant has no more than 200 miles on it. Their thought was it could be a turbo issue. I called my normal mechanic and he was skeptical. I am too. In the 60k miles I've put on the car, the turbo sounds and behaves exactly as it did on the day I bought it. For now I've decided to sit tight and wait to see if the cooling issues appears again. But I'm still concerned because I drive this car regularly into the middle of nowhere for outdoorsy pursuits (as Subaru PNW owners tend to do). What if the issue suddenly appears on a logging road in the woods? Does anyone have any thoughts or suggestions for next steps? I'm seriously at a loss here besides just keeping an eye on things.
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Last edited by PNW_Ullr; 06-22-2018 at 06:58 PM. Reason: Grammar |
06-22-2018, 04:36 PM | #2 |
Trust no one
Moderator Member#: 11170
Join Date: Oct 2001
Chapter/Region:
Tri-State
Location: NYC
Vehicle:02 RAV4 MT 15 WRX/11 CRZ |
Have you checked to make sure the fans are coming on? If they aren't you will get the symptoms you have described, normal temps when moving at speed and rising temps when stopped once the car has been driven for a while.
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06-22-2018, 05:12 PM | #3 |
Scooby Newbie
Member#: 487504
Join Date: Jun 2018
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The fans are operating normally. When I pulled over during the first overheating event they were at maximum speed. My primary mechanic confirmed they are operating as expected.
Last edited by PNW_Ullr; 06-22-2018 at 07:00 PM. Reason: Grammar |
06-23-2018, 08:46 AM | #4 |
NASIOC Supporter
Member#: 30669
Join Date: Dec 2002
Chapter/Region:
Tri-State
Location: USA, North NJ, 07456
Vehicle:1998 Legacy 2.5GT Silver Sleeper BK, 5MT |
Does your coolant level change a lot? From cold to normal it should rise maybe 2" in the overflow tank.
If you check every morning when cold, it should always be about the same level. If it rises a lot when warm, you likely have air in the system, cold interior heat is a sign of that. |
06-23-2018, 12:13 PM | #5 |
Scooby Newbie
Member#: 487504
Join Date: Jun 2018
|
Actually now that you mention it the overflow reservoir was unusually high when the temps were spiking.
Also my primary mechanic flushed the coolant during the 90k, which could've created an air bubble. He also said the radiator was low when I brought it in for the overheating problem, so he topped it off. Maybe we've been jumping to dire solutions for a simple problem. |
06-23-2018, 12:51 PM | #6 |
Scooby Specialist
Member#: 283429
Join Date: May 2011
Chapter/Region:
South East
Location: Down yonder.
Vehicle:2016 Fuji Sunfire 03 Silver |
Did the first shop put in a new thermostat? Either you got a flakey thermostat or the beginings of head gasket failure. Additionally that low coolant level could indicate a failed/incorrect radiator cap on the engine reservoir or - head gasket failure. Yes, air bubble from a 90K might be a cause, but after 1500 miles maybe not. The tell for that would have been an empty overflow with a cold engine.
Assuming this is head gaskets and not thermostat/rad cap: You kinda shot yourself in the foot here. Coolant replaced less than 200 miles ago, haven't had an overheat event since then, of course the new shop won't find evidence of a head gasket leak. Assuming this is head gaskets and not thermostat/rad cap: Based on your description you have caught this very early and are experiencing the intermittent failure that proceeds a total failure. The engine has to get to operating temp for the right amount of time under just the right amount of load. At that point the head warpage (there will be some when you measure the head) will increase and allow some combustion gas into the cooling jacket. This creates an "air" bubble and causes the spike in temp and heater issue. Once it cools down it closes again. This will continue until the gasket becomes too damaged and the hot spot increases the head warpage. One thing to be aware of - when this happens that air bubble displaces coolant (higher level in the overflow) and decreases the ability for the cooling system to create the vacuum when the engine is cold that sucks coolant back into the system. Then you have air in the system. That compounds the hot spots that makes the heads warp. It's a domino effect from this point forward. See the disclaimer about rad cap... Assuming this is head gaskets and not thermostat/rad cap: I would go ahead and do the repair for the simple fact that they will have to cut less material from the head when they resurface and less likely to get pitting on the sleeve face and head from the burning jet of combustion gas that is going through the leak when it occurs. |
06-23-2018, 01:00 PM | #7 | |
NASIOC Supporter
Member#: 30669
Join Date: Dec 2002
Chapter/Region:
Tri-State
Location: USA, North NJ, 07456
Vehicle:1998 Legacy 2.5GT Silver Sleeper BK, 5MT |
Quote:
I usually jack the front of the car up, open top cap (NA or turbo), start, let warm (have interior heat to full hot), as it warms squeeze upper radiator hose, when bubbles seem to stop/lessen, install cap, shut off engine, make sure overflow tank is a little overfilled. Drive, watch the overflow, add as needed. The level drops when the system burps air and sucks in liquid. May take a few days, just watch the overflow and add as needed. Report back. PS, interior to full heat circulates coolant through the cabin which is part of the cooling system. Air in the system (pull radiator cap, level low.....or, loss of cabin heat) will expand more than coolant, thus overfilling the overflow tank and what seems like a bad HG. |
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06-23-2018, 01:04 PM | #8 |
NASIOC Supporter
Member#: 30669
Join Date: Dec 2002
Chapter/Region:
Tri-State
Location: USA, North NJ, 07456
Vehicle:1998 Legacy 2.5GT Silver Sleeper BK, 5MT |
I see Elbert Bass weighed in while I was writing.
I have yet to see a warped head or block on a Subaru NA with failed HG's. I HAVE seen warpage on turbo Subaru engines with bad HG's, not always, but more common. |
06-23-2018, 03:40 PM | #9 |
Scooby Specialist
Member#: 283429
Join Date: May 2011
Chapter/Region:
South East
Location: Down yonder.
Vehicle:2016 Fuji Sunfire 03 Silver |
Charlie-III - Must be different climate or something. In the 7 years I have been working exclusively on Subaru 70% of all n/a EJ engines from 2000 and up I have repaired for head gasket leaks or blown gaskets have warpage greater than maximum allowable.
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06-23-2018, 05:18 PM | #10 | |
NASIOC Supporter
Member#: 30669
Join Date: Dec 2002
Chapter/Region:
Tri-State
Location: USA, North NJ, 07456
Vehicle:1998 Legacy 2.5GT Silver Sleeper BK, 5MT |
Quote:
I did work on a 2002 WRX that the owner bought "reconditioned heads" and a quick check showed head HG surface out of spec. I showed him how to resurface with an appropriate flat plate and paper. Still running well almost a year later. Maybe the earlier EJ heads for NA were a bit more robust? I have no clue. I have done a dozen or so (mostly 2.5L) NA HG's and a couple 2.2's. Blocks and heads were well within limits. Not arguing, just stating what I have seen/dealt with. |
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06-23-2018, 09:20 PM | #11 | |
Scooby Newbie
Member#: 487504
Join Date: Jun 2018
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Quote:
Update Welp, this afternoon my Dad and I popped the hood ourselves to take a look. With a cold engine we popped off the radiator cap and fired it up. I gave it a bit of gas and large bubbles started to form. Then I stuck my nose in the radiator opening and smelled exhaust. Looks like I'm going to be road tripping up to Bellingham again for the repair after all... Thanks for the help and insights everyone! Last edited by PNW_Ullr; 06-24-2018 at 01:29 AM. |
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