Heavy Si

I've been trying to figure these 3 issues and wonder if they might be connected.
The manual says I should have 135 psi compression with open throttle. 3 testers all agree that I have 200-205 psi on all 4 cylinders.
The idle is slightly rough but was worse before I switched to 93 octane fuel. And the heat is warm at best. I have drained, flushed and back flushed the engine and heater core separately. I have changed the thermostat and the gauge seems to be at the right place once the engine finally warms up. I have also bled the cooling system using a radiator mounted high reservoir and used fresh Honda coolant.
Any thoughts would be greatly appreciated. I want to work on getting more power from the motor but have no idea what may have been done to the car before I bought it with 99,500 miles on it.

ezone

Sounds perfect to me.


Not sure about roughness.

If heat is poor, sometimes you have to get the heater core and hoses burped manually.....air gets trapped in the highest points and you have to remove the hose(s) from the heater pipes at the firewall to get the trapped air worked out. I stick my funnel on the radiator and fill it so the liquid level is much higher than the heater core and hoses, then remove the heater hoses slightly so trapped air can be released. Push and move the hoses so any air trapped in high spots can be moved to the burp point.

Every car can be different, some are much worse than others to get trapped air burped out.
Sometimes a couple good blasts up to redline on the road can burp the core too. Not always.

RIPSAW

Ezone fixed your problems. But at 100K and 14 year old car, I would drive it easy and forget any additional HP. Just my opinion. PS..did you use a OEM thermostat? Aftermarket stats are JUNK.

Heavy Si

Pretty sure the heat is due to a bad thermostat again.
Much more concerned with the high compression and rough idle.
As far as the age and mileage go, if a car is properly maintained, age and mileage won't matter. I've had modified cars with over 300k miles that were driven hard daily without problems.

Heavy Si

"3 testers all agree that I have 200-205 psi on all 4 cylinders. Sounds perfect to me."
If spec is 135 psi how is it that 205 psi sounds fine?




















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Heavy Si

[QUOTE=ezone;4701772]Sounds perfect to me.


If spec is 135 psi how can 205 psi be fine?

Reverb2005

You're only worried about the lower pressure limit, not the upper. The more pressure you can hold back the better the seal. A higher pressure number means you have a better seal around your pistons.

ezone

Real world experience:

I expect 180+ on almost any Honda engine of recent vintage, and many will hit in the 200+ range if it's in decent shape and has good cranking speed.


If I only get 135 PSI using my testers and my methods, the engine has a huge problem.



Also, it is possible that if a cam has jumped time it can raise compression numbers, but I've not been witness to this. I've seen plenty with a compression loss when a cam is out of time.

Wankenstein

Did you do a wet (with small amount of oil ) test too?

Read: http://www.whatcouldbegreener.com/14...will-cost-you/

You probably did this but I am going to ask anyway:
1) Bled air from coolant while front end is raised on jack stands
2) Bled air from coolant with interior heater on max heat
3) Bled air from coolant while pumping and feeling for heat either the lower and/or upper radiator hose
4) Flushed coolant system while thermostat was out
5) Insected/tested radiator cap, reservoir hose for clogs, reservoir inlet for clogs
6) Check waterpump by watching coolant flow in radiator while revving engine and at operating temp

I am just regurgitating was it said over at the Honda Tech site when, on a daily basis, someone ask about power gains for 7th gen civics:
Turbo! Anything else is a waste of money. Bolt-ons will net you very little HP or torque.

sdaidoji

iTrader: (1)

funny... most are worried about low compression...

also, could just be carbon buildup