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'98 Legacy 2.5L N/A will not start after rebuild


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Hello all, I'm sorry to have to come here in this fashion, rather than bringing something to the table, but I am at a complete loss and need HELP! My son and I just rebuild the 2.5 in his Legacy after it spun a rod bearing. Before that it ran fine, though he hasn't owned it for very long at all. There are lots of details of headaches and heartaches with this car after buying it from a dishonest seller. However, I won't take you down that rabbit trail.

So, the engine will turn over and sound normal then fire and run for about a half second, then die. After that, it will crank and try to to hit, but never start. If I put the throttle wide open, it will start and spit and spudder and try and bounce out of the engine bay, but never get over a few hundred RPM.

Any advice will be greatly appreciated.

 

This is all that checks out good:

Timing

Spark (good at plugs)

Fuel (wet plugs, and lots of volume to injectors)

TPS (.509 volts)

Crank Sensor (2KOhms)

Cam Position Sensor (2KOhms)

MAF (cleaned but not tested)

Knock Sensor (replaced just before spun bearing)

Ground (good connections, but added temporary 8ga wire from block to battery)

All sensors and plug connections checked

No trouble codes

I took pics of the timing marks before we tore the engine down, and while two of the marks are a half groove off, it ran like this before. Pics before and after below for reference.

Before

43840171775_b2bcd138e8_b.jpg

After

44030399464_2d754b4c06_b.jpg

29812394897_c12e8aaeba_b.jpg

Before

43840144745_5faf88ee27_b.jpg

After

30878545818_f24932cb7d_b.jpg

43840119145_c08b243971_b.jpg

 

Before

44030416244_7fc47e3eb3_b.jpg

After

43840123505_167e6e0ab9_b.jpg

 

I will post a video of it cranking over as well.

 

Edited by 98GT
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I had a similar issue once after swapping to a 2.2. Did you happen to remove the TPS when the engine was pulled or just prior to reinstalling it ? It is easy to install it wrong due to the fact that the TPS isn't in the proper position for install in it's relaxed position. 

 

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mine wasn't quite like yours in that mine would start and barely run and it never got over a few hundred rpm and then died. I quick test of the TPS with your Ohm meter while opening and closing the throttle will either prove or disprove this. If your ohms don't go up and down in relation to the throttle position then remove your TPS and open the throttle just a hair and hold it while reinstalling the TPS

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did it 'throw' the rod?, any new cam pulleys? any broken teethe on the back of the crank pulley?

3 - 4 cheap/easy ideas;

triple check the IACV hose

do a tooth count on the timing (you can find the tooth count online, yours 'looks' OK, just a cheap/easy suggestion)

I know you said it looked like you had good fuel, but you could try feeding some starter fluid or even propane into the intake when starting, if it gets worse, yeah plenty of fuel, if it gets better - fuel starved?

scan again for pending codes?

Edited by 1 Lucky Texan
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50 minutes ago, 1 Lucky Texan said:

did it 'throw' the rod?, any new cam pulleys? any broken teethe on the back of the crank pulley?

3 - 4 cheap/easy ideas;

triple check the IACV hose

do a tooth count on the timing (you can find the tooth count online, yours 'looks' OK, just a cheap/easy suggestion)

I know you said it looked like you had good fuel, but you could try feeding some starter fluid or even propane into the intake when starting, if it gets worse, yeah plenty of fuel, if it gets better - fuel starved?

scan again for pending codes?

Check, Check, Check, on the hose

Did not throw the rod, just spun it and was shut off as soon as the knock was heard

Same pulleys that came off and all teeth are good.

I tried carb cleaner into the intake with zero change in results

Have scanned for codes multiple times. It had a TPS code the first time, but after adjusting it, the code did not return.

6 minutes ago, montana tom said:

Just for ha ha 's unplug the MAF and see if it will run.

Tried that one too, with same results.

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Thanks for the suggestions fellas. Even though I have done all of the suggestions, I'm sure one that I haven't tried will pop up eventually. I'm going to pull the intake today and look for a pinched or broken wire in the harness, and basically start back tracking. Also, my son didn't get the oil pan sealed up good, so the engine will be coming back out to fix that. I will do a compression test on it right before that happens as well.

Edited by 98GT
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  • 3 weeks later...

Sorry for the late reply. I broke the screen on my Macbook and have not had a computer for a couple of weeks.

After what seemed like hours of backtracking, I discovered the drivers side camshaft sprocket was not installed correctly. I was not present when my son put all the sprockets back on and it was just clockwise off the key way a couple degrees. Something I should have caught early on, but the little pin in the sprocket had pushed out when he tightened the sprocket down, allowing it to spear to seat properly. the pin is not cast into the sprocket, so it is capable of backing out, so that's something people should keep in mind during installation.

Now, it runs good, but has a bit more lifter tick than it did before disassembly as well as an oil pan leak that just doesn't want to be fixed. I will be pulling the engine out one last time myself this week to address the leak as well as checking the valve lash and making an attempt to fix that as well.

On another note, the weirdest thing was going on with the cooling system. we could never seem to get the air out of the system and over the course of a couple days managed to fit 4 gallons, yes 4 GALLONS, of coolant in the system. I'm pretty sure these engines only take like 2 gallons.... No coolant leaks, internal or external, and no blown head gaskets. Where did the extra 2 gallons go? I have no clue.  Anyway Thanks for the replies from you guys, and sorry for the wild goose chase of something that was operator error all along.

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On 10/14/2018 at 5:42 PM, 1 Lucky Texan said:

wow, well, good catch on that cam pulley.

 

um, I guess start checking oil, trans, and cylinders and ? for the coolant....not sure what to say on that.

Ive not been able to look at the car yet because I've been pouring concrete in front on my shop this past week. I'll be pulling the car back in the shop on Sunday and getting back on it.

On 10/14/2018 at 7:49 PM, GeneralDisorder said:

If the extra 2.5 gallons of coolant isn't in the oil or on the ground it's gone out the tail pipe. 

These don't have hydraulic lifters so valve lash is suspect. 

Oil pans are glued on and usually don't leak. Check the separator plate, rear main seal, and the dipstick tube. 

GD

I'll be pulling the engine Sunday I hope. Since we rebuilt the engine, the pan was off. He pulled the engine again after discovering the leak, and tried to fix the leak, but obviously didn't seal the pan well enough,,,again! This is why I will be doing it myself this time. As far as the valve tick, since it wasn't ticking before rebuild, and we didnt rebuild the heads, I suspect my son got some of the valve buckets out of place, causing one or more to no longer be in spec. I am hoping I will measure them all, and find one tight, and one loose, and swap them. I'll report back on my findings.

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  • 2 weeks later...

Got and update on the current engine issues. I got it pulled out once again, removed the oil pan, which was leaking on the back side...again. Cleaned it up straightened the lip a little here and there, and resealed it. On the stand, and while the timing belt was pulled, I filled it up with oil, pulled the spark plugs, WD-40'd the cylinders, and put a big 1/2 drill motor on the crank bolt and spun that sucker up as fast as it would go, in order to spin the oil pump and build up some crank case pressure. So far no leaks are present. I placed paper towels under the engine covering the area, and will be checking for signs of oil leaks tomorrow.

While out, I addressed the loud top end. I carefully went through all 16 valves with my feeler gauges and recorded all the valve lash numbers. I had about a half dozen out of spec. I was able to address the worst ones, 0.06-0.07mm too loose, by swapping around the disks/shims that sit on top of the buckets with each other, bringing them into the proper spec range. I still have 2 or 3 that are 0.01mm too loose, but they will just have to do.

And finally I addressed the coolant consumption issue, in what I consider, a thorough way. First, with the engine on the stand, I capped the upper and lower hose necks, as well as one of the heater lines. The other heater line was hooked to a ball valve and male air coupler. After filling the engine up with water, I hooked a regulator to the line, and slowly brought it up to 20psi, closed the ball valve and let it sit for 20 min. Oh, before I pulled the engine, I did get some compression readings. All cylinders were around 200psi, give or take a few psi, so I really had my doubts on a blown head gasket, but did the test anyway. After sitting for 20 min, I hooked the drill up, with the plugs out and spun the engine. ZERO water was present in the cylinders. I preformed the same water/pressure test on the radiator and heater core. The radiator passed with no leaks, but I did have one, somewhat significant leak at a hose connection at the fire wall. While a pretty good leak, It's still hard to believe that it went through 4 gallons of coolant in less than 100 miles, and never left a water spot on the ground. After fixing the leak, I pressurized the system and had a slow leak down on pressure, but no more water leaks present anywhere in the heater core system. So, with that said, I am still a little wary of the coolant situation, but I've done all that I know to do.

I'm anxious to get this thing back in the car, but it's looking like it will be Sunday before that will happen. Fingers crossed!

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The problem is that if the HG's are the source of the coolant leak it will not show up on a compression test AT ALL, and checking for pressure drop with the engine cold will show nothing. They only leak when they get hot. 

If the engine is out of the car - resurface the heads and replace the gaskets. Check the block for any pitting in the fire ring area. 

GD

Edited by GeneralDisorder
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Not really - you say it used 2.5 gallons of extra water.... that did not apparently end up on the ground - and being these engines usually don't leak from the HG's till they are up to full operating temp - I wouldn't expect to see much on the plugs or pistons, etc. Extended running may show some steam cleaning of the piston tops - if they were otherwise coated in carbon.

New head gaskets are frequently installed wrong, the surfaces prepped wrong, or the bolts tightened wrong. For whatever reason this happens quite often on Subaru's - especially to those who aren't initiated into the ways of the Subaru engine. So when I hear that an engine has these symptoms but the HG's were "just replaced by shop X"  - my immediate gut reaction was they did the job wrong. I've seen it probably hundreds of times now. It's ridiculous how common it is. 

GD

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