EJ2-Fluffy

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Here's my dilemna, my car as it sits now has a stock D16z6 steup w/ a header and exhaust, and my car has been overheating after a short 30 minute drive (highway or city). Also, much of the overheating is blowing out of the coolant reservoir container.

First, I checked the exhaust system and the muffler has alot of carbon coming out the back of the muffler. You can literally rub your finger in the exhaust hole and alot of black soot will be on the finger.

Second, I checked to see if the radiator was bubbling. I took off the radiator cap, filled the radiator to the top and ran the engine cold. I waited for the car to reach optimum temperature and hardly saw any bubbles. Although the flow of the coolant seemed to be very slow, I can tie it maybe to the water pump failing.

Third, I checked the Valve Cover. While the engine was still running at idle, I popped open the oil cap and it seems to be pushing out alot of pressure.

Here is a video of a rag over the valve cover with the oil cap removed.

http://www.youtube.com/watch?v=vjArOsEmGcU

Notice the pressure that is being ventilated. Im guessing the exhaust seals could be messed up or the valve guides.

P.S. Also have a new head with a new headgasket, but I want to make sure what the problem to see if I need to toss the new head on or just replace the water pump and prevent removing the head.


Can anyone help me out to diagnose why my car might be overheating.


Thanks,
Jon


Modified by EJ2-Fluffy at 3:47 PM 5/23/2007

EJ2-Fluffy

iTrader: (1)

bump

P_QUINONES

i get the same problem without the overheating. wonder what it is

EJ2-Fluffy

iTrader: (1)

Thanks for the reply? Anyone else?

dohcdelsol

plan on doing a headgasket in the short future.

blow back into the resv. is signs of air in the system. you already blead the system and its still happening? i would bet the headgasket wasnt done right.

EJ2-Fluffy

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<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dohcdelsol &raquo;</TD></TR><TR><TD CLASS="quote">plan on doing a headgasket in the short future.

blow back into the resv. is signs of air in the system. you already blead the system and its still happening? i would bet the headgasket wasnt done right. </TD></TR></TABLE>

The system has been bled and checked. The engine has rougly 70k miles (or thats what the previous owner explained to me when purchasing the car) and that the engine was never rebuilt.

This is what its come down to.

Yesterday, I tested the system. Filled the radiator upto the neck, and left the coolant reservoir empty.

Note: This is still with the pressure blowing out the oil cap (feels like the exhaust pumping out the valve cover - happens with all RPMS)

Got back home last night and checked the level this morning. The coolant reservoir tank was filled halfway and dumped back into the radiator. However, the radiator didnt fill up all the way back to the neck, rather, it filled up all the way to the bottom.

My assumption, the engine is overpressurizing the coolant fluid and causing it to go into the coolant reservoir. And the coolant the radiator needs, is causing the car to overheat.

However, my question will the pressure from the valve cover be a cause to this?

EJ2-Fluffy

iTrader: (1)

Valve cover pressure - what is it?

instructor74

Don't worry about the pressure in the valve cover right now. If you want to get to the bottom of this do a compression test. It really sounds like you have a bad head gasket with that engine being original and with almost 80k on it. Honda did a redesign on the head gasket for that motor in the late 90's do to the large number of HG failures at around 80k. Check your compression normal failure you will see low compression on a few cylinders my exp it has always be #2 and #3. You could also test your coolant for exhaust gasses if present it is a blown head gasket.

Bakeoff

you're over complicating things.
First, set a piece of paper over the oil cap hole. You SHOULD notice that it will pulse up and down, or hopefully not move at all. The pulses of air moving in and out will always feel like it is just puffing out.
Now, if you really do have positive pressure, you're probably looking at bad valve seals. But then you're probably be burning oil.
It sounds like you ahve a head gasket that is blown. It doesn't always blow coolant into the cylinder, but often does. It can result in a stumble at any throttle angle, but is not always consistent. Sometimes it will drive just fine.
You may not have oil and coolant mixing, depending on where it blew. But when the cylinder compresses, the pressure is forced through the leak in the head gasket, and will create positive pressure in the cooling system. Coolant normally only runs up to something around 10psi when the engine is warm. So, anything above that will cause the coolant to blow back in the reservoir since the system is over pressurized.
If you keep driving it, you WILL warp the head. It may be warped already, depending on how far you've let it go. But you definitely need a new head gasket. You'll also need to have the head checked, and may need to have your block decked. All of this could have been caused by a bad thermostat, originally.
But the longer you let this go, the worse off your engine will be. Get coolant in your oil, and it will thin it out. Next thing you know, you're spinning rod bearings, ******* up the crank, cam journals, and anything else it wants to destroy.

EJ2-Fluffy

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<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bakeoff &raquo;</TD></TR><TR><TD CLASS="quote">
First, set a piece of paper over the oil cap hole. You SHOULD notice that it will pulse up and down, or hopefully not move at all. The pulses of air moving in and out will always feel like it is just puffing out. </TD></TR></TABLE>

If you watched the movie link i posted, that is what it is doing. Puffing in and out.

EJ2-Fluffy

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by instructor74 &raquo;</TD></TR><TR><TD CLASS="quote">Don't worry about the pressure in the valve cover right now. If you want to get to the bottom of this do a compression test. It really sounds like you have a bad head gasket with that engine being original and with almost 80k on it. Honda did a redesign on the head gasket for that motor in the late 90's do to the large number of HG failures at around 80k. Check your compression normal failure you will see low compression on a few cylinders my exp it has always be #2 and #3. You could also test your coolant for exhaust gasses if present it is a blown head gasket.</TD></TR></TABLE>

I ran a compression test and the numbers across it were pretty even, +/-10 between each one.

Although, if the headgasket was blown, I would be seeing coolant in my oil, and that isn't the case.

How do I go about checking if exhaust gases are present in the coolant? I can already smell the gaseous/oily smell in the coolant, but how can I be positive and sure?

instructor74

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EJ2-Fluffy &raquo;</TD></TR><TR><TD CLASS="quote">

I ran a compression test and the numbers across it were pretty even, +/-10 between each one.

Although, if the headgasket was blown, I would be seeing coolant in my oil, and that isn't the case.

How do I go about checking if exhaust gases are present in the coolant? I can already smell the gaseous/oily smell in the coolant, but how can I be positive and sure?</TD></TR></TABLE>
you are not going to always have oil and coolant mixing with a blown head gasket. I have done 2 on my motor one at 85k and the 2nd at 216k neither one had any mixing of coolant and oil. Both did have pressure build up in the rad pushing coolant into the over flow. the 1st had low compression on #2 and #3 the second only had a small compression loss on # 3 cylinder. I caught both really early

Edit: as far as testing for the gasses in the coolant you could take it somewhere but I just read on here the other day that there is a kit you can buy to test for it

EJ2-Fluffy

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by instructor74 &raquo;</TD></TR><TR><TD CLASS="quote">
you are not going to always have oil and coolant mixing with a blown head gasket. I have done 2 on my motor one at 85k and the 2nd at 216k neither one had any mixing of coolant and oil. Both did have pressure build up in the rad pushing coolant into the over flow. the 1st had low compression on #2 and #3 the second only had a small compression loss on # 3 cylinder. I caught both really early

Edit: as far as testing for the gasses in the coolant you could take it somewhere but I just read on here the other day that there is a kit you can buy to test for it</TD></TR></TABLE>

Ahh thats good to know. Well I already have a built head and new materials to put a new head on.

However, is it normal to have pressure coming out of the oil cap location (when the cap is off) when the engine is idling?

EJ2-Fluffy

iTrader: (1)

Can anyone answer the question, should there be any pressure coming from the oil cap location when it is idling?

EJ2-Fluffy

iTrader: (1)

bump its buggin me haha

jayjay

Yes, there should be pressure coming from the oil cap hole.

The oild drains run down to the lower end of the motor. The piston stroke on the way down is what causes this pressure. This is why the pcv valve is a one way valve.

Also,
After reading your post. I am leaning more toward a blown head gasket. Although if you have not bled the coolant correctly. You may have air locked in the system. This will cause coolant to boil over into the over flow.

my 2 cents.

sqsi

I had a similar issue on my 92 si. It blew a lot of coolant out the overflow bottle. It ended up being a bad radiator. I had done the t-stat and all the hoses , then thought bad headgasket as well. but figured I would end up getting a new radiator down the road anyhow so i got one at the local autoparts and no problem since. It was odd

EJ2-Fluffy

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jayjay &raquo;</TD></TR><TR><TD CLASS="quote">Yes, there should be pressure coming from the oil cap hole.

The oild drains run down to the lower end of the motor. The piston stroke on the way down is what causes this pressure. This is why the pcv valve is a one way valve.

Also,
After reading your post. I am leaning more toward a blown head gasket. Although if you have not bled the coolant correctly. You may have air locked in the system. This will cause coolant to boil over into the over flow.

my 2 cents.</TD></TR></TABLE>

U sure about there being pressure in the valve cover? Usually on motors in domestic cars there should be no pressure coming out of the valve cover. Although, there is a PCV system right on the valve cover on the older 60's ford 289's. But if the valve seals are doing their job, shouldnt there be no pressure? The pressure seems like it is tied to worn exhaust valves.

99Civic-EX

my car has the same problem, i thought it was the thermostat but it still does it too, so im doin my headgasket which is what i was told by almost everyone

jayjay

Are you talking...

the kind of pressure that would push an empty soda can off the hole or the kind that would push a full soda can off?


If you valve seal were that bad..

You would be buring a good amount of oil.

EJ2-Fluffy

iTrader: (1)

if you watch the movie in the link above it shows what kinda pressure is coming out of the engine

jayjay

I took the time to set up my speakers and listen to your video clip. Sounds like either a floated valve or a stuck valve.

Did you run a compression check?

EJ2-Fluffy

iTrader: (1)

car is taken apart - yeah it ran a straight 140 +/- 10 across

jayjay

post your findings..

EJ2-Fluffy

iTrader: (1)

looks like the headgasket was leaking past the number 3 and 4 cylinders. You can tell by the oil ring mark on the cylinders themselves. Seems like there was alot of calcium build up. I might have not completely flushed the system correctly leading to lots of calcium on the coolant block walls.