kr2k

I don't normally post on forums but i'm fed up and lost this time.
Order of events
<3 years ago> 130,000 miles

• Burnt 1 cylinder exhaust valve.
• Rebuilt top end ran great

<5-6 months ago> about 180000 miles

• Car has trouble starting after warmed up, kinda like vapor lock.

<5 months ago> about 180500

• notice white smoke while backing out of garage.
• Do a compression check and leak down test, results come out normal (no problems)
• Determine that its leaking from cylinders 3&4, no milk in oil.
• Make an educated guess and replace intake gasket (Didn't trust, it was a cometic thermal gasket, seemed sketchy when I installed it when I did my first rebuild. )
• Did notice the the gasket was cracked, between the last stud hole and coolant inlet.
• After replaced IMFG still smoking.
• Pull top end back apart, pressure check head, check for warping, replace head gasket and reassemble, still smoking
• Read a post about the Idol air control value causing the car to burn coolant when the gasket goes bad.
• Disconnect coolant lines from IACV and no smoke.
• Put lines back on car, still no smoke (Strange)
• Drives great for about 2 weeks no issues other than a CEL light for smog pump thing, no smoke, no milk.
• One day it starts up really rough, after a short drive the car refuses to start up; turns out it was water logged.
• Replaced IACV

<Present>

• Runs Fine sometimes (Not really operable other than testing),
• Sometimes it overheats for short periods of time 4 to 5 bars, cools once it hits 5 bars (Car smokes while this happens) runs like poo after.
• Seems to be a lot of pressure in the coolant system now.
• Bad T/stat? Possible Air in lines? Bad Radiator Cap? Could any of this cause it to temporarily burn coolant though?
• ...
• Currently water logged again.

At a loss, Any thoughts or similar experiences?

kr2k

Current CELs
Misfires 1 - 4
P0411 - Secondary air injection system, not sure what this does.

fredsvt

At this point, it sounds as if the engine is toast. Running at 4 bars is 239, TOO hot. 5, ugh.

Being hydrolocked (not waterlogged), is deadly for connecting rods, if you've tried to start it and it's hammered and locked up against liquid in the cylinders, you can easily bend rods at the least, break them in the right situation.

It sounds like you had a slight head gasket leak, that gradually got worse, along with possibly not bleeding the system completely at one of the refill situations.

Time to take the head off again, sending the head to a good machinist to have the head checked for warpage, cracks and if it needs straightening or replacement. The block deck needs to be checked for straightness and cracks and the liners need to be checked for cracks near the top on cylinders 3 and 4. How did you clean the block surface at last disassembly? Hopefully not with roloc discs. Did all the head bolts take torque properly, feeling tight? None pulled threads at near torque spec?

The cylinder walls if scuffed, well, are done. If not, at the very least, it'll need to be re-ringed. The oil control rings will lose all their tension from that kind of heat.

Spartarus

What did you do with those coolant lines to the IAC when you disconnected them?

I have a theory...

A couple of them actually.

Sticky thermostat. Explains overheat and cooldown.
Air in the system after removing IAC lines.

While the thermostat is closed, water still flows through the system. There are 3 bypass paths.
1. Oil cooler
2. Throttle body and IAC
3. Straight pipe from rear block outlet to water pump inlet.

When hot, with air in the system and a stuck thermostat, it wouldn't be a stretch to assume that the pressure in those 3 small bypass channels is sufficient to force coolant past that tired old O-ring in the IAC valve. It's the weakest link. That's the most likely source of white smoke. When the thermostat pops open, pressure in the bypass lines drops significantly. Car stops burning coolant.

When you overheat a coil pack, it doesn't work right. There's (possibly) your misfire.

Regarding running like crap after overheat: Detonation causes ECU to pull timing. Car runs like sh*t. Turn the car off, counter reset. Runs fine next time because the ignition timing is back to normal.

kr2k

Thanks for the replies.

I mean waterlogged, it will turn over, just wont start because the plugs get wet. I'm going to save taking the top end of again until I have exhausted all other options, that intake is a bitch to get off. If it comes to that I think ill just get a new engine... I hope Honda designed their engines good enough to withstand a few short over heats.

Makes sense Spartarus, Ill try a new thermostat, change the oil and see if that does the trick. Ill let you know what happens.

janders111

A head gasket leak could be pushing air into the cooling system, explaining the intermittent overheating. What you can try is cranking the engine with the radiator coolant cap off, and see if bubbles come out of the radiator. A better version of that test is shown here:

I have done both head gasket and engine swap. Head gasket job would probably be worth it since the engines in these cars are getting sooo expensive. The heads are fully rebuildable. Blocks are not, hence why they are so expensive. But your higher mileage and compression numbers would be factors.