Coolant overflowing? Blown Headgasket? Compression Numbers! Need assistance - Honda Prelude Forum

krazyshane · 04-18-2006, 04:03 PM

Okay... well same symptoms... Car is spitting all the coolant into the overflow tank and then overheating. The coolant is foamy and bubbly and there is a "false boil" -- air bubbles, but not hot). However, the coolant looks brand new and clean.

If I drive it hard (vtec) it will spit it out quicker and be very foamy... if i drive it long, it will do the same (long and easy highway cruises). On short easy trips, it's okay.

I've thought it could be the headgasket now for a while... any time you see foamy looking antifreeze, it is a sign, but i've had no other headgasket symptoms. Runs fine, no burning coolant etc.

Well, today i picked up a compression tester kit and got my numbers. Here they are:
210, 202, 202, 202 (the 202s were between 200 and 205)

Those numbers look great to me. So what the hell is going on w/ my car.

It's hardly driveable. Is it possible for the headgasket to leak after the car is warm, but not while it's cool (explaining the short trip thing)? Because i tested compression w/ a cold engine.

Shane

SNsLude · 04-18-2006, 04:06 PM

Yah I'd try a compression test after the car is warm too... maybe the heat will expand some things and reveal maybe some tears or something somewhere on the head gasket that is hiding right now...

a possibility. But as for now, those numbers don't really indicate anything with the head gasket unless it's blown evenly around the last 3 cylinders

besides, those are great numbers regardless so I think even if you had some tears some where in the gasket it would be far less than what you got.

PreludeChick89 · 04-18-2006, 04:29 PM

when my headgasket went in my 3rd gen.. there was some indication in the coolant (milkey foamy like yours).. it never did what you described...I'd say it sounds like a headgasket problem for sure though.. it may just be a matter of time before it completely goes and leaves you stranded.. i wouldn't suggest chancing it like i did..

my car got temperature guage darted straight up.. made a train sound, no gas response and died.. thought all of it was just a headgasket until i found a bunch of corkscrews in my oil pan..

krazyshane · 04-18-2006, 05:51 PM

Ahem... those number were not WOT... i forgot to do that. They were w/o any gas being applied.

I heated up my car and tested it WOT (I remembered)

cylinder 4 read 240!
cylinder 3 read 235!
cylinder 2 read 200 ...
cylinder 1 read 170.

I was like WTF? So I went back to cylinder 4 to make sure the gauge was okay and it only read 185 the 2nd time...

I waited a bit, tested them all again

4 - 185
3 - 185
2 - 185
Battery going dead, didnt get good cranks on 1 BUT
1 - 175.

I'm not sure i can trust the gauge now. Because i read 240 and 235 for a bit and then crap.

Can we go by the cold numbers in the beginning of this thread even though i was not WOT?

Shane

jackazz · 04-19-2006, 10:01 AM

I just did a compression test myself. It was my first time, so I was glad that my new tester came with instructions

First let the car come up to operating temp. Then disconnect the main spark plug lead (forget the right name for it, but it's the one not on the distributor) and hook it directly to ground. Then, at WOT, try cranking the car until you get at least 4 compression strokes. If you have a helper, have them check the gage. You are supposed to crank until the gage doesn't go any higher. That is your compression number.

The 235 and 240 seem a bit high, btw.

krazyshane · 04-19-2006, 05:23 PM

well... I heated up my car and tested everything again today (just recharged battery)

Here's the readings:

185,190,185,185... Good numbers...

I am not 100% sure if my gauge is working now, because how do i get a reading of 240 1 time on cylinder 4 and then in the same conditions read 185?

Can gauges break by softly hitting metal? I mean, like if i'm cranking and it slides off what i'm bracing it on and hits the FI unit, that wont break the gauge will it?

I dont really know what to think now. I'm still going to need to go somewhere and have it diagnosed.

Shane

jackazz · 04-19-2006, 05:42 PM

It is highly unlikely that a light impact, such as the one you describe, could damage the unit. The 185-190 numbers seem reasonable. Also, before you decide to take some sleeping pills and go walking into the Gulf, the Helms manual says that a nominal measurement for compression would be 180 psi. The lower threshhold is 135 ( I believe - I looked it up earlier this week). Those compression numbers don't seem bad.

Just thought of this. Have you had any work done on your cooling system recently? Radiator replacement, coolant flush, heater core replacement, etc? You may have an abnormal amount of air in the cooling system that is trying to work it's way out. You may want to open the radiator cap (when engine is cold), start the car and let it start to warm up. It may begin to spit bubbles out and suck down the water level. Keep adding coolant until the level doesn't go down at all. Be sure to do this until the thermostat opens up completely (engine reaches operating temp).

Perhaps this will solve your problem. Keep us posted.

SNsLude · 04-19-2006, 05:57 PM

He bled his coolant system just a few days ago iirc. He had some air pockets but he got rid of those. Hmmm, i dunno shane, try taking it to a shop to do a compression test for you. Shouldn't cost much or maybe even anything.

Stereodoc · 04-22-2006, 11:08 AM

Do you know if the thermostat is working properly? If the thermostat isn't opening it'll cause the cooling system to puke.

marcucci · 04-22-2006, 02:55 PM

Do some searching. You are probably not doing the test right. You have to crank the car enough for that cylinder to come to TDC at least once which can take a few seconds or more when cranking. I generally hold for 10 seconds to get a good reading.

Head gaskets on the 4g and 5g just quite simply don't blow. Honda switched to a multi-layer-metal (MLM) gasket on the H22 which has virtually no chance of failing. A failure is usually due to improper installation or something more severe, like a damaged head, compromised cylinder, etc.

krazyshane · 04-23-2006, 06:51 PM

Quote:

Originally Posted by marcucci

Do some searching. You are probably not doing the test right. You have to crank the car enough for that cylinder to come to TDC at least once which can take a few seconds or more when cranking. I generally hold for 10 seconds to get a good reading.

Head gaskets on the 4g and 5g just quite simply don't blow. Honda switched to a multi-layer-metal (MLM) gasket on the H22 which has virtually no chance of failing. A failure is usually due to improper installation or something more severe, like a damaged head, compromised cylinder, etc.

Thanks for the reply. I cranked on each cylinder about 6 times for 2-3 seconds each, So i'm sure I got to TDC. And my numbers of 185,190,185,185 are good.

Going on that and what you said.. what could it be other than my headgasket?

The coolant is filling up the overflow bottle to the point that it's too low on fluid. I have bled the sysem several times, and I have changed the thermostat. What else could it be?

Shane

springgeyser · 04-23-2006, 09:44 PM

TDC doesn't matter with a compression test. A leakdown test is done at TDC.

WHen the car is hot, the coolant will flow into the overflow tank. As the engine cools, the radiator will suck the coolant back form the overflow.

krazyshane · 04-23-2006, 10:12 PM

I understand normal operation..

The problem is that it is spitting TOO MUCH coolant into the overflow tank and sometimes causing it to overflow or bubble over (despite the liquid not be boiling temp -- I can put my finger in it)... There is also a false boil. This also causes the car to overheat because it fills the jug to the top always.

Shane

marcucci · 04-23-2006, 10:30 PM

Quote:

Originally Posted by springgeyser

TDC doesn't matter with a compression test. A leakdown test is done at TDC.

You're wrong. You don't position the engine at TDC, that's true, but you have to crank the engine long enough for the cylinder to go through an entire intake/compression cycle (and hence TDC after the compression stroke) to get a value that means anything. You don't develop any cylinder pressure on the intake stroke before compression, or on TDC after the exhaust stroke before the next intake cycle.

2-3 seconds isn't long enough, period. Do it at least 7 seconds and I can almost guarantee you that's where the 185 to 205 variance came from.

If you truly have compression in the cooling system, you have some breech between combustion gases and coolant, period. As I've mentioned I have yet to see this except as the result of improper assembly or some kind of cylinder/head damage. t-stat and rad cap shouldn't matter when it comes to a "false boil". I would do a leakdown and pressure test the cooling system and try and figure out where the coolant is going by sight or sound.

springgeyser · 04-23-2006, 11:36 PM

Wasn't wrong just didn't feel like explaining it in detail. In his other post, he already stated the pressure test for his cooling system came out fine which I already suggested a leak down to see if the pressure leaked into the cooling system.

krazyshane · 04-24-2006, 10:26 AM

^^ Leakdown test will be my next thing. I'll have that done at honda i suppose

I'm tired of trusting other mechanics..

Shane

springgeyser · 04-24-2006, 08:54 PM

I trust Honda dealer mechanics even less. It the quantity, not the quality that's the dealership's focus.

krazyshane · 04-26-2006, 04:26 PM

Well... I went to a radiator place I trust next to my parents company. They tested the antifreze for compression gasses and found none. He determined it then to be a flow problem. Took the radiator apart and found a small crack on one of the tanks...

Could repair the tank or replace the radiator (for $40 difference -- due to labor) so I replaced the radiator w/ a new one. Now waiting on a new thermostat from honda (overnighted) so i will pick the car up tomorrow. I really hope this ****s done w/ after this.

Good to see no compression gasses in the antifreeze though

Shane