ThosL Posted September 5, 2015 Share Posted September 5, 2015 I had a chance to just check the compression on my four cylinders in my 99 OB with the 2.2. Going passenger side to driver side back, results were around 120 for the first three and 100 for the last. Is that the one usually affected by bad head gaskets? Thanks. Link to comment Share on other sites More sharing options...
Fairtax4me Posted September 5, 2015 Share Posted September 5, 2015 Were all 4 plugs removed? Was the throttle held wide open? If not, need to do it again. Link to comment Share on other sites More sharing options...
johnceggleston Posted September 5, 2015 Share Posted September 5, 2015 all 4 removed on a warm engine with WOT, wide open throttle. Link to comment Share on other sites More sharing options...
ThosL Posted September 5, 2015 Author Share Posted September 5, 2015 I pulled one plug at a time, putting them back in afterwards. I started the engine several times on each cyl. and checked the compression each time. Link to comment Share on other sites More sharing options...
Fairtax4me Posted September 5, 2015 Share Posted September 5, 2015 That's dynamic compression. That's a bit different. Dynamic compression changes based on engine Rpm and load. Was the engine totally warmed up? It needs to be warm for an accurate dynamic test. Link to comment Share on other sites More sharing options...
ThosL Posted September 5, 2015 Author Share Posted September 5, 2015 Yes; but I did notice a range of compression readings.....Cyl closest to driver was weakest; is that where the head gaskets tend to leak? Link to comment Share on other sites More sharing options...
Rooster2 Posted September 5, 2015 Share Posted September 5, 2015 On a 2.2 motor, I am unaware that a bad head gasket will cause a poor cylinder compression reading. I have had a 2.2 phase 1 motor, and a 2.5 phase one motor blow head gaskets. Both resulted in exhaust gas allowed to enter the cooling system with resulting over heating. Is the motor you have phase 1 or phase 2 ?? A bad head gasket in a 2.2 phase 2 results in coolant leaking out of the engine, shows as spots on the pavement under the car. Link to comment Share on other sites More sharing options...
Fairtax4me Posted September 5, 2015 Share Posted September 5, 2015 Yes; but I did notice a range of compression readings.....Cyl closest to driver was weakest; is that where the head gaskets tend to leak? You won't typically notice a head gasket leak with any kind of compression test. The buildup of compression happens more quickly than it can bleed off through a leak in a head gasket. Low compression is more likely to be a valve problem, or worn piston rings or cylinder wall. Lower compression during a dynamic test could even be due to a slightly different air fuel mixture in one cylinder. Do a static test. All 4 plugs out. Unplug the fuel injectors and the coil or igniter to disable fuel and spark. Hold the throttle wide open and crank the engine for 5 pulses. 1 Link to comment Share on other sites More sharing options...
Rooster2 Posted September 5, 2015 Share Posted September 5, 2015 I guess I am missing something. What problem is this motor having that diagnosing for a compression check is needed?? Link to comment Share on other sites More sharing options...
lstevens76 Posted September 5, 2015 Share Posted September 5, 2015 Thos has a ton of various posts you can look up as to his problems with this car and the steps he has been taking to diagnose it. At this point though I would just order an Evergreen Full Engine gasket set + Fel-Pro or OEM gaskets, pull that engine and replace the gaskets. IIRC the thermostat, water pump, and radiator have already been replaced. That leaves only the heater core, hoses, and head gaskets left other than possibly the ECT providing incorrect readings. And yes I've dealt with a BHG on a 2.2, it just isn't very common. And if the leak is not "severe" as mine on my 2.2 was your never going to see a compression problem. Link to comment Share on other sites More sharing options...
ThosL Posted September 6, 2015 Author Share Posted September 6, 2015 I would do the head gasket replacement if I had the experience and the place to work on it which I don't. If you know someone in the NY area who would do the whole thing under $700, including parts I would probably go for it. But sometimes you get what you pay for.....I drove around 100+ miles today and just overheated on the way back but not terrible. The steam bubble in the coolant system develops and putting the heater on to suck heat out does not then work. I'm within striking distance of 300K miles. Link to comment Share on other sites More sharing options...
johnceggleston Posted September 6, 2015 Share Posted September 6, 2015 (edited) ....Cyl closest to driver was weakest; is that where the head gaskets tend to leak? ej22 head gasket do not tend to leak. i would look for another cause before i opened this engine up. of course it could be a head gasket, not unheard of, but i would look into it more. i'm not convinced you have accurate compression readings. and i'm not convinced it isn;t a timing issue. but i'm sitting in my den in VA, not touching your engine. good luck. Edited September 6, 2015 by johnceggleston 1 Link to comment Share on other sites More sharing options...
ccrinc Posted September 6, 2015 Share Posted September 6, 2015 Bad head gaskets aren't going to have any real effect on cylinder compression. And you certainly can't diagnose where a head gasket has failed/is failing by compression readings. Normal compression is considered ok if it's within 10-15% on the cylinder readings. More than a 20% difference can cause the engine to run rough. By now, anyone who's followed your posts knows that you have overheated this engine many times. And that it's a high mileage engine. I think it's a testament to the reliability of this engine that it's even still running! I must say I am still puzzled at to how your Outback has a 2.2 engine in 1999. It HAD to have been changed out at some point, because the only engine that was sold in that model and that year was the EJ25 DOHC version. Link to comment Share on other sites More sharing options...
ThosL Posted September 6, 2015 Author Share Posted September 6, 2015 It did have the transplant of a 2.2 a few years ago for around $1500 which I highly recommend. And I agree other problems can arise leading to similar symptoms; heck, the head gasket sealant products can wreck the radiator, other leaks than the ones I have known about and fixed myself; thermostat issues, etc.. Unfortunately every mechanic I have spoken to about it assumes head gaskets are the cause. Steam and bubbles could be caused by other things. Link to comment Share on other sites More sharing options...
lstevens76 Posted September 7, 2015 Share Posted September 7, 2015 With all the overheating and adding coolant what's your coolant to water ratio? One thing that can cause bubbling is a low coolant mixture where the water can still boil. Just a thought. Link to comment Share on other sites More sharing options...
ThosL Posted September 7, 2015 Author Share Posted September 7, 2015 No anti-freeze at this point; though I have a gallon in the back seat I may use when the leak or boilover problem is resolved. At $13 a gallon no sense in having it guzzle out in a couple days. As far as I've heard the only problem that develops without antifreeze is rust. Higher boiling points are of little benefit with the problems that can cause, but I know loss of water can follow hot temps.. Link to comment Share on other sites More sharing options...
lstevens76 Posted September 7, 2015 Share Posted September 7, 2015 Ok, average running temperature of a car: 185f to 210f depending on the brand, model, etc... Boiling temperature of water: 212f You get slightly warmer than running temp (for a subaru can vary from 195 to 210) and your boiling water. What your also forgetting is the higher elevation and lower ambient temperatures can cause water to boil below 212f. Then you also have to factor in that depending on outside conditions water can give off steam and evaporate at lower temperatures than normal as well. In other words it wouldn't be hard to have the system giving off steam which is evaporating out the overflow hence lowering the coolant level and causing increased heat for the water to boil. Link to comment Share on other sites More sharing options...
ThosL Posted September 8, 2015 Author Share Posted September 8, 2015 Thanks for the analysis. So when I go to a mechanic for diagnosis and he sees bubbles in the radiator overflow tank, and assumes head gasket issue rather than ask more questions do more research.....And once the system starts getting hot you have a chain reaction; water gets pushed out and worse issues follow and it could seem that you have what you don't have. Plus air bubbles in the system can be hard to purge. Link to comment Share on other sites More sharing options...
Fairtax4me Posted September 8, 2015 Share Posted September 8, 2015 Have a leakdown test done to confirm a bad head gasket. At this point, it's been overheated enough times that the gaskets are probably compromised anyway. Water boils at 212 but the system is kept under pressure which raises the boiling point. Which is how American cars can run at 220° and not boil over. Also the reason why radiator caps say "do not open when hot". A system at 210° and under pressure can boil once that pressure is released. Link to comment Share on other sites More sharing options...
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