Cranks but will not start?

Hi,

The compression is too low. If everything was checked and good, my first suspect is the timing is off.

If you look at the pic below, it shows the manufacturer's specs for compression. The minimum is 142 PSI, and you are well below that.

Try testing compression wet. Add about a tablespoon of motor oil into the cylinder through the spark plug hole and see if the pressure goes up a good bit.

Let me know what you find.

Joe

See pic below.

Thank you, Joe.
I didn't open full throttle when I checked the compression to see if that makes a difference. I'll redo it and will let you know. I'll also re check the timing chain just to make sure that I didn't mess it up while bolting everything up.

Hi,

You are very welcome. It doesn't seem right to have low compression after all that was done.

Recheck the compression to confirm. If it is still low and you confirm the timing is correct. perform the wet test with oil to see if the pressure goes up.

I will watch for your reply.

Take care,

Joe

Hi Joe,

So, finally removed the valves cover and spun the crankshaft to align the cams arrows... cams don't line up at all at TDC. No idea how that happened because I thought I lined it up perfectly. I'm assuming it has to do with the VVT crap... anyway, what's the easiest way to realign all 3 marks without removing the timing chain cover?
Thank you in advance.

Hi,

The marks won't align with every rotation. You may have to turn the engine several times for it to happen. If I had to guess, I would say you are only one or two links off.

As far as alignment, I don't think you can do it without removing the cover. The crankshaft keyway has to be at 12 o'clock and you can't see it with the cover on.

Take a look through the directions below. Let me know your thoughts.

Also, I am reading through the extensive procedure the manual supplies. In the exploded view, it shows one timing chain. The directions are showing two. Before I send all of this, let me know if you have one or two chains.

Take care,

Joe

See pics below.

Hi Joe,

Thank you for the info... So, you're right that though the chain marked links never align every time, the timing appears to be spot on with cams/crank marks. So at least that part is good.
Here's what I discovered this morning: compression is very low, just about 75 on #1 #2 #3 cylinders and just about 100 on #4 calendar. This was with throttle wide open. Adding a couple spoons of oil increase it a little but still nowhere near good enough.
So, at this point my suspicion is head gasket leaking.
Little history: reason for the teardown was because the five head bolts on the intake side were stripped causing the engine to cease. I did the time insert thing and replaced the 5 inserts and was able to torque it down to the 58ft/lp +90°. Is it possible that they're not torqued down well enough?
New pistons, new rings, machined the head, honed the bores... looked pretty darn good to me.
Should I have coated the head gasket? It was uncoated, maybe I need a better grade head gasket? It came in a kit from rock auto so I'm not sure.
I've done engine rebuilds before so I'm pretty meticulous usually.
Thank you again.

Hi,

When the cams aligned, was the crankshaft on top dead center? Also, when you checked the compression, did the pressure bleed off quickly?

Let me know. I would not like to see you have to tear everything apart again and find it was something simple. Also, your torque specs are exactly what they should be.

Take care of yourself,

Joe

Hi Joe,

Yes, that's correct marks on cams aligned with the crankshaft at the zero "0" mark on the chain cover which is TDC.
My compassion gauge is one of those that builds the pressure while cranking the engine and you'd have to press the valve to release the pressure so I wouldn't know if the pressure is holding... maybe I should go borrow a better one from AutoZone/advance auto?
When the head came back from the shop, I measured it for straightness, and it was perfect and so was the engine block... so I know mating them with a head gasket in between should be perfect. So, I really don't know what's going on. I also took out all 16 valves, cleaned them and replaced their seals. They looked good to me.

Hi,

If the compression gauge has a button you push to release pressure, you should be able to watch if it drops fast before pressing it.

By chance, do you have someone cranking the engine when testing or do you do it yourself? If you are doing it yourself, you may not be seeing the true pressure.

Let me know.

Joe

Oh I see what you mean... in that case no the pressure doesn't drop fast and maintained until I press the button to release it.
I usually place the pressure gauge high enough that I can see it while cranking for about 5-6 seconds. I usually stop cranking when the pressure stops climbing.
I'm gonna grab a loaner gauge hopefully later to give it a try... who knows, maybe my gauge isn't good and pressure isn't the issue
Thank you again Joe.

Hi,

No problem whatsoever. Hopefully, it is just your gauge, and we are dealing with a much easier repair. LOL

You take care of yourself and let me know what you find.

Joe

Hi Joe,

Unfortunately, the compression output is the same as mine... the first three are just about 70 PSI and with a spoon of oil I can get it up to 90ish. #4 gives about 100 PSI dri reading.
The pressure in all 4 doesn't leak fast but nevertheless still low.
I'll re-check the valves clearance once I remove the valve cover but I doubt that I'll find any discrepancy there as I checked clearance a 100 times before putting the timing chain on.
At this point I'm thinking i may have to open her up again... what thinks you?

Hi,

If the valves are good and it holds the compression it produces, the only other things would be a bad head gasket or the rings. Did you check the end gap on the rings? I remember you had the block machined and bored. Did you get the correct oversized rings?

Joe

Hi Joe,

Sorry for the confusion... I did not send the block to the machine shop, only the cylinder head was sent to the machine shop... came back looking great. The valves were never changed, only the seals on the valves were replaced.
I honed the engine block at home myself... i used the hone tool i purchased from harbor freight. Did a good job on it I think...
Keep in mind the 2 middle pistons were pretty bad, but I did not see any serious damage to the block bores to send it to the machine shop. It is possible that the block requires machining and the use of a larger jugs... not sure if this car is worth all that trouble considering its age 220,000 miles on the transmission.

Hi,

That is where the problem likely is. Did you install new rings? How much did you take out with the hone?

I attached directions for checking the end gap on piston rings. I have a feeling the cylinders are worn and the rings and that's why it isn't building compression the way it should.

When you said it was bored, I figured there were new pistons and rings as well. And no, you can't replace the cylinder walls. If you could, it would be more expensive than buying an engine. You can bore them to a point and use oversized pistons and rings, but it isn't worth the effort.

Take a look at the attached and let me know your thoughts.

Joe

See pics below.

Thank you again Joe.
Just for clarity, I replaced all the pistons and the rings with the standard size.
I think you're right; the rings gap may have been slightly on the higher side of the scale causing the low compression I'm getting.
I don't think it's worth it for me to machine the block and then replace all pistons and rings with over-sized one all over again.
I'll see if I can find a block in better shape than mine, otherwise I may part-out or junk the car.

Hi,

I hope you find a good one. How many miles were on the engine you rebuilt?

Joe