Replaced head, now surging issues
 

Hi all,

I just replaced the head on my 97 civic cx. It was running great even with the warped head. It started up fine and ran for about 10 minutes fine. Then it began to surge at idle, dropping in RPMs sharply then returning to normal. The check engine light hasn't come on. It is still on jacks in my driveway, I haven't driven it yet, but it seems that the surging stopped when I hit the gas.

My question is; is there any common surging issues that arise after a head replacement? There are so many possible causes, I'm having trouble narrowing it down. The car has been sitting for about three months, is it likely that old gas could be the problem? Or perhaps air in the coolant, a/c, or gas lines? Or is it probable for one of the chips to be a problem?

Thanks,
Chris

simply bleed the coolant system. and that should fix the issue.

Bleed the coolant, check all your vacuum hoses, and the gas could be a problem too. Try running a bottle of sea foam when you get new gas. I usually put it in my gas, crank case, and fuel injectors. Also might try cleaning your IACV.

i dont think it could be your coolant and fuel making it surge at idle.... my 94 civic is doing the same think and it the IACV.... another possible thing could be fast idel valve on the trottle..

yeah mine was doing that to it was the fast idol valve just take it out and clean it really well

Update:

1) While trying to get the air out of the coolant, I ran the engine with the heater on full. While I did this, there was no surging issue. Immediately after turning off the heater, the surging returned. Might this be evidence of an IACV problem, or related to air in the coolant system?

2) I ran the car idling for 10 minutes with the heater on, the top radiator hose got hot but the bottom remained cold. Does this mean the thermostat didn't open?

3) There appears to be sludge or oil in the coolant at the radiator cap. I don't think I flushed it properly after the initial head damage. Are there any causes for this not related to a blown head gasket that may be contributing to the surging problem?

I can't tell if I'm looking at one problem, or a bunch of small problems. Any suggestions would help, thanks.

-Chris

it might... the oil could kinda foam in the system... just a maybe. id definatly flush it tho...

head gasket replace fail
 

It seems now that the head gasket replacement failed. I'm getting oil in the coolant and white steam or smoke out the tail pipe. My guess is either the gasket didn't set right or the engine block is damaged (unless there is another cause for white smoke and oil in the coolant).

1) So new question, can a busted head cause surging or am I still looking at 2 separate problems?

2) I've tried bleeding the air out of the coolant, following instructions here and in the manual. I still don't know if I was able to get the air out though, because there is no air bleed valve on my 97 civic cx hatchback. Any clues on how I can be sure the air is out?

3) I took off the AICV and cleaned it. When the engine is running and I unplug the electrical connector to the AICV the rpms drop down, so I think that means the valve is functional?

4) There's no FITV on the 97 civic with a d16y7, so I don't think that's the problem... I found that the surging is less likely to occur when i have the air filter and air filter housing removed.


The way I see it now is I can't afford to try to fix the head again. If I can get the surging to stop, maybe I can get a few miles (to the bus station) on it each day until I can get a new ride.

well it defenitely sounds like another head gasket... did you make sure that the head was strait before you put it back on? check the block as well.. either of them might need to be plained.... i just did the same thing to my 94 civic dx...

when you unplug the IACV the rpms drop but it still kinda surges but not as bad?
the oil might be getting in the valve and messing with it...