i bought a 96 accord from my neighbor for $800 because he thinks it has a bad headgasket. he told me it was running hot so he took it somewhere, and they said they found carbon from the exhaust in the coolant and that they thought it had a bad headgasket. i took the car home and it definately ran hot on they way home, almost to the point of overheating. so i brought the car to the shop i work at to give it a good look over. i found that the coolant in the radiator was slightly low so i topped it off. i have now driven the car a couple times and the tempature gauge has never even gone half way up. it seems to be fine but i have not run a compression test on it yet. if the compression test turns out to be good then is there any other way to diagnose a bad headgasket besides a compression test? thanks in advance.

 

A leakdown test will test rings, valves and headgasket all at the same time.

 

if you have access to a 4 gas you will be able to check the cooling system for h/c's anything over 75 is a bad thing.

 

Putting an exhaust gas analizer in the radiator tank is one way, but not advisable. The glycol vapors wreck havok with the sample elements.

A compression / leak-down test will make a blown head gasket quite apparent. The art of observation is a lot cheaper, if you know what to look for.
A blown head gasket will has several indicators which you can look for.
A coolant system pressure test spanning (about an hour) may also help spot a head gasket.

A) If the car smokes out the exhaust a WHITE smoke, you've an internal coolant leak (Head Gasket, cracked sleeve etc). If it's grey smoke - you're burning oil.
B) If you loose Antifreeze (coolant) and can't (for the love of GOD) find it; you may have a blown Head Gaslet.
C) If your crankcase is overfilled (and you can't remember the last oil change) with water beads on the dipstick .... you know the answer.

P

 

Uh oh... my 96 Accord is smoking white smoke out the exhaust. I kind of smell a gas smell too. I have to work on this in the weekend and it's getting freezing out here.

Internal Coolant Leak, hmmm I checked my levels and they were fine.

 

The kind of white smoke I'm talking about is the consistant / any tempurature white smoke, not the just started in the morning white condensation smoke which disappears once the exhaust warms up. It is always accompanied with a sweet nondiscript odor caused by the glycol burning.
it will be quite apparent.

The carbon in the exhaust you first mentioned... Normal, Normal Normal.
If it's a grey / white carbon, it's a normal unleaded fuel byproduct. If it's a black carbon, the car is either running rich (too much fuel) or has been driven on primarily short trips (and never heated up)

P

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by P_Adams &raquo;</TD></TR><TR><TD CLASS="quote">The kind of white smoke I'm talking about is the consistant / any tempurature white smoke, not the just started in the morning white condensation smoke which disappears once the exhaust warms up. It is always accompanied with a sweet nondiscript odor caused by the glycol burning.
it will be quite apparent.

The carbon in the exhaust you first mentioned... Normal, Normal Normal.
If it's a grey / white carbon, it's a normal unleaded fuel byproduct. If it's a black carbon, the car is either running rich (too much fuel) or has been driven on primarily short trips (and never heated up)

P</TD></TR></TABLE>

my car does not smoke or have the odor you describe. im just going by what the guy i bought it from said. he said the shop found carbon desposits from the exhaust in the coolant.i topped off the coolant and im gonna drive it or a week to see how much coolant it consumes. i dont think i can get my hands on a leak down tester so im gonna do a compression test this weekend but im not sure if im even going to bother fixing it. i need this car to be good and reliable so i may just pick up a used engine and tranny and drop it in there, i dont know though. the engine just feels kind of tired(maybe due to loss of compression from headgasket?) and the transmission shifts kinda rough so i dont know if i even want to put the money into it if the engine or transmission is gonna **** the bed in the middle of winter. what do you think? is it worth it?

 

If he predicated his diagnosis on the presence of carbon in the exhaust pipe, I wouldn't value his diagnostic ability (at least for cars.
If you have a garage in the Syracuse, NY area 9and you can get the car there; invest a few dollars and have both a compression test and a radiator leak-down test performed.
This will give you a definative answer as to the engine's health.

P

 

Carbon deposits in the coolant, maybe, HC traces, more possible with a 4 or 5 gas analyzer but coolants have HC's on a regular basis, sniffing for CO is the better test with a gas analyzer but it can kill the analyzer if any liquid gets sucked up, AutoZone should sell a chemical test for the coolant, check it out, I forget if it tests for CO or HC.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by P_Adams &raquo;</TD></TR><TR><TD CLASS="quote">If he predicated his diagnosis on the presence of carbon in the exhaust pipe, I wouldn't value his diagnostic ability (at least for cars.
If you have a garage in the Syracuse, NY area 9and you can get the car there; invest a few dollars and have both a compression test and a radiator leak-down test performed.
This will give you a definative answer as to the engine's health.

P</TD></TR></TABLE>

i dont think your understanding what im saying. obviously there is carbon in the exhaust pipes. i think the shop he took it to meant that there is a leak between the combustion chamber and the coolant ports in the head from the headgasket. i work at a general maintenance shop and im perfectly capable of doing the headgasket. i just dont know a whole lot about engine diagnostics. i have a radiator leak tester and compression tester, i just dont want to buy a leakdown tester cuz money is tight right now. now about the radiator leakdown test. you can only pressurize the cooling system so much. the pressure in the combustion chamber is much greater than the pressure you can put in the cooling system. if the leak is small will the radiator leak down test even show any thing?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Duane_in_Japan &raquo;</TD></TR><TR><TD CLASS="quote">Carbon deposits in the coolant, maybe, HC traces, more possible with a 4 or 5 gas analyzer but coolants have HC's on a regular basis, sniffing for CO is the better test with a gas analyzer but it can kill the analyzer if any liquid gets sucked up, AutoZone should sell a chemical test for the coolant, check it out, I forget if it tests for CO or HC.</TD></TR></TABLE>
ok dont laugh at me cuz i know this is gonna sound stupid but what is CO and HC? this is probably common sense im just retarded


Modified by redline870 at 11:18 PM 10/21/2008

 

CO = Carbon Monoxide
CO(2) = Carbon Dioxide (for reference)
HC = HydroCarbons

P

 

An engine drinking your coolant, you are only thinking compression, how can 15 PSI of radiator pressure leak into a cylinder of well over 100 PSI compression. Remember it is a four stroke engine and one of those strokes is INTAKE.

What is the OTHER name of an Internal Combustion (IC) Engine, a VACUUM PUMP, do you think this would be a good time to get coolant into the combustion chamber not to mention the possibility of the Exhaust stroke, that is extremely low pressure too.

The other issue is that the radiator probably is not holding a full 15 PSI since it is leaking, cooling systems only can pressurize one time due to the heating and expansion of the coolant mix, once it is fully hot and pressure is released, it does not re-pressurize, there is no pressure pump, only expansion of the fluid during its heating process.

Get the car fully warmed up, use extreme caution and several rags to open the radiator cap, reseal the cap, go for a drive around the block, it the hoses are pressurized again then it looks like you have a blown head gasket, sometimes you need a longer drive but you get the idea.

Put your coolant system pressure tester on the cap, keep it pumped up for hours (in your case), pull the spark plugs and motor over the engine, coolant should spray out of one of the spark plug holes, blown head gasket is found. Keep it pumped up all day I would say.

You do not need to buy a nice leak down tester, build you own, does your compression tester quick disconnect (between the gauge and hose) on the hose fit into your shop air hose (my Sears does, my Snap On does not), if so you have a 90 PSI (or whatever your shop air is) pressure tester. Put the cylinder to be tested at TDC and hold it there somehow, screw in hose, hook up shop air and listen for a leak out the intake, tailpipe, radiator cap area and oil dip stick tube. Bubbles from the coolant, blown head gasket found. Dont forget cylinder to cylinder leaks so air could blow out of the cylinder spark plug hole next to the one being pressurized but that is not your case.

 

cool thanks a ton for the info both P_Adams and Duane_in_Japan. i really appreciate you guys taking the time to leave me detailed responses. now i have really good idea of where to start. i will try a few of these ideas tomorrow and let you know how they work out for me. thanx again!

 

ok so the only thing i had time to do today was a compression test. i think the order went 190-190-180-200. what do u think about that?

 

It's healthy. Even for a car half it's age.

P

 

is it possible it could still have a slightly leaking headgasket though? i think it may be slowly consuming coolant and there is no other leaks

 

I have found D series engine with the front center head bolt had become loose. You may want to re torque the head. Just set the torque wrench a few ftbls below spec and torque them all, then set the wrench to spec and torque them.


Had a mechanic use a HC tester to check for a HG leak once. with the radiator cap off, engine running, he only had to get within 3 or 4 ft of the radiator and the tester showed HC.

 

whats the compression supposed to be? my haynes manual says 178 psi. that doesnt sound right. and whats the torque settings for the head bolts? thanx

 

where can i get a HC tester? autozone doesnt have one

 

It's not so much what the compression figure is as much as the differentiation between the highest reading and the lowest. A ten (10) percent varience between cylinders (in your case 17psi) is considered acceptable.

If you had gad a result of 170, 70, 60, and 175, I would have raised a flag. I would suspect the head gasket between cylinder 2 and 3.

Another thing to watch for if you suspect a head gasket:
The cooling system will sometimes start blowing bubbles in the Coolant Recovery Tank as the system over-pressurizes. You will also see A LOT of bubbles circulating thru the radiator (if you're brave enough to open the cap.

P

 

-no white smoke
-no glycol burning smell
-no access to HC tester
-no access to leakdown tester

-slight coolant consumption
-coolant consumption led to running hot in the past
-oil had not been changed in a while and was still right to the top despite leaking valve cover and oil pan gasket. leads me to believe coolant was getting into the oil giving it the apperance that it was in fact full. drained oil but i didnt see any coolant in it, just looked dirty. ??

im so frustrated!!! i may just quit the guessing game and just replace it anyways even if its not bad. it doesnt sound very hard to do and i have no access to a HC tester which i feel if the only true way to tell if theres a leak. i feel like all the other 'signs' of a bad headgasket are only aparent when the gasket is leaking badly. the leak may be really small now and not showing any real symptoms except for slight coolant consumption, but with my luck it will blow on me in the dead of winter.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by P_Adams &raquo;</TD></TR><TR><TD CLASS="quote">Another thing to watch for if you suspect a head gasket:
The cooling system will sometimes start blowing bubbles in the Coolant Recovery Tank as the system over-pressurizes. You will also see A LOT of bubbles circulating thru the radiator (if you're brave enough to open the cap.</TD></TR></TABLE>
so are you saying to open the cap when its hot and look for bubbles? i'll take the cap off when its hot, im not scared of that, wont the coolant would just pour out of the radiator? and is this where im supposed to look for bubbles.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Duane_in_Japan &raquo;</TD></TR><TR><TD CLASS="quote">The other issue is that the radiator probably is not holding a full 15 PSI since it is leaking, cooling systems only can pressurize one time due to the heating and expansion of the coolant mix, once it is fully hot and pressure is released, it does not re-pressurize, there is no pressure pump, only expansion of the fluid during its heating process.</TD></TR></TABLE>
i havent tried this test yet but will give it a try tomorrow.

what is the compression supposed to be on a f22b2?

 

I would not suggest opening a radiator at ooerating tempurature. Opening it cold will surfice. IF you've got a blown head gaasket (and I emphasise the word IF), a failed gasket will be readily apparent when you start the car.
It should start blowing bubbles long before the thermostat even opens.
Don't open a presurized cooling system Hot, second degree burns are not fun.

If it means peace of mind, go ahead and change it.

It's just that I'm not to that point of recommending it myself.

P

..it's better to make no recommendation than make a bad one.

 

bluish white smoke...coolant in the oil...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hatchness135 &raquo;</TD></TR><TR><TD CLASS="quote">bluish white smoke...coolant in the oil...</TD></TR></TABLE>

wow i think we already covered that...

P_Adams- i pulled the cap off today started the engine and sure enough consistent bubbles were coming out. thanks for the help and tips! this was the defining moment. i have a new headgasket and will be replacing it on sunday. thanks again man! any tips for doing the new one? i heard the intake and exhaust manifold can be left attached to the head? cuz i didnt get a new manifold gasket.