ttl

Had my timing belt and water pump done.
After that, a week of no heat at idle but blowing hot when diving 2000 rpm and greater. Antifreeze overflowing from overflow tank and antifreeze not going back into rad from overflow tank when cool.Thought it was going to be a head gasket.
Changed the rad cap and all is good now. Heat all the time and coolant flows in and out of the overflow tank as it should....thank god, wasn't looking forward to a huge HG bill. Cheers

Matt_75

Pretty amazing how a rad cap could cause all that. You might want to consider doing ezones bad HG testing just for peace of mind, which involve blowing ~170 psi of air in to each cylinder via the spark plug whole and look for a steady stream of bubbles coming out of the radiator. It would probably look something like ezone's video linked below.

BlueEM2

iTrader: (1)

Yes we all have access to 170 psi of air.

Matt_75

No need to be an azzhole dude. He could take to a shop and ask them to perform the test.

ezone

Check this out: https://www.civicforums.com/forums/1...ml#post4629441

BlueEM2

iTrader: (1)

Not trying to be an ***... Just saying it's true Most shops misdiagnose head gaskets so frequently its ridiculous. If you go up to them and say apply 170 psi of pressure to each cylinder they will just diagnose it their way anyway

ezone

I have used this method (among several other methods) for literally decades now, learned back in the olden days when the Dead Sea was just sick.

When I started in this shop nearly 10 years ago, this was a novel and new idea to these guys. I suppose I brought a whole bunch of fresh ideas to the table.





Some people might have 25 years of experience....
Others might repeat their first year 25 times.




Sad but true. Reminds me of a quote:
The fool exists always, and the prime characteristic is that while you can readily make a wise man feel uncertain about his wisdom, it is absolutely impossible to make a fool doubt his wisdom. His every failure is someone else's fault, or evil influence of sheer bad luck, or he always has some answer. ~John W. Campbell~

ttl

Well I spoke too soon..It still blows cold air when at idle but only after coasting down a hill. Then stays cold until I rev it up for a bit. When driving on flat ground and I come to a light it drops down from hot to warm air but not cold. Going up hills or reving, it's hot hot hot...
Car never overheats, so I'm guessing air lock in the system??? I think I will get a combustion leak test done though, just to be safe.
Any other suggestions on what could cause this? thx

Matt_75

Combustion leak test probably won't reveal anything. If you can't do the shop air think, I would recommend doing what ezone already said and attach a hose to your overflow port on the radiator and put it in a bucket of coolant. Start the car and look for a trail of air bubbles as seen in his video he posted above.

Mine never overheated either when I ended up replacing mine. I came back from a highway trip. I remember the air conditioning was acting a little funny, periodically blowing warmer than normal air, but I didn't think anything of it. Temperature gauge never budged. When I pulled in to my park stall, I decided to check the oil level. Popped the hood and coolant was all over the trans, fans, battery etc. Reserve tank was full to the top and when I popped off the radiator cap there was no coolant to be seen.

Anyway, my HG saga is in the below link.

https://www.civicforums.com/forums/3...ppened-me.html

Good luck with whatever you find. It's really not that bad of a job if you're mechanically inclined. If not, make sure you have somebody reputable change it for you if you determine it's the HG.

ttl

I've heard that that combustion leak test will tell if there are hydrocarbones in the coolant, showing that there is a blown hg, or not.
Wouldn't you see bubbles coming up in your overflow tank, without having to use a bucket?

Matt_75

I would do a search for blown hg's. There's about a zillion threads out there and decide for yourself what you need to do.

ezone

If this test does show the problem, that's great.
Problem is, this test doesn't always show the problem. That leads to misdiagnosis.

Passing a test may only mean you didn't do the right test.
Good thinking.....

Yes, if you can really see the whole thing.
One can't always see into a reservoir clearly and unobscured (various vehicles).

Plus, the radiator cap does not vent the pressure in the cooling system until it has about 15PSI in it, it remains under pressure which can seriously slow or stop the "bubble production" (until the engine is under a load).

My goal is to prove it FAST and prove without any doubt (or disprove, as the case may be).
When I post here, my first thoughts usually are NOT of how a DIY'er may have to do things.
My methods may not be the most convenient for some people, but they serve me very well.

BlueEM2

iTrader: (1)

I'll also bust a myth right now. No heat during idle is not a head gasket problem directly. It's actually caused by air or exhaust in your coolant system. Air bubbles passing through the heater core will not provide heat. Even if your head gasket is blown you can remedy this by bleeding the coolant system. However, if the HG is gone it will eventually repeat itself and the problem will resurface. Like I said, replace your rad cap, bleed the coolant system. If the problem comes around again you can be sure it's the head gasket.

e-zone I like that quote. I'm also glad you do things the right way, I wish I could say that same for 99% of other shops including most Honda dealerships.

ezone

^^^True. Airlock.
(Trapped air actually impedes the flow of liquid through the heater circuit, but same effect. Raising the RPM increases the water pressure and temporarily overcomes the "blockage".)

But an airlock doesn't just happen for no darn reason.

If a customer brings one in, I don't have the luxury of sticking a cap on and telling them to come back later on (that's considered misdiagnosis if it doesn't fix the problem). My goal is to solve the problem right now. Personal pride in my work, and accountability.
Others might stick a cap on and blow it down the road because solving the problem either is too difficult or the pay sucks.

Thanks, I try.
I use quotes like that against management.

ttl

Took the car into Honda and told them what was happening. They looked at it and said thermostat is stuck but hg is ok. They replaced the therm and did a flush, charge me 250 for the therm and flush. I get the car back and drive 2 blocks and its even worse now (even more air in the system)..lol So I take it back and the head mechanic takes a look, gets a little air out and then says, well maybe it is a hg. I dont think they even did any tests to check for a hg, other than look to see if there was water in the oil or steam coming out of the exhaust.
I plan to take the car back today and either get my money back or money off the hg bill. I thought these clowns would be able to figure this out first time?

ezone

Let's clarify here: Your local dealership.



Management thinking:
All cars have 4 wheels, therefore they are all the same.
Everyone with a shoebox full of tools has exactly the same talents and abilities.
I don't understand it, therefore it must be simple.
Would you like fries with that?

Dilbert?

ttl

Yes to the local Honda dealer. They are replacing the head gasket as I speak. $1200
Yes experience is eveything, when trouble shooting a vehicle. Apparently the first Mechanic had vey little...He should visit this site and gain some.lol
It will be nice to have it running properly again.
Am I wrong or is this a fairly common problem with 7th generation civics?

ezone

Far too many have no interest in bettering themselves.




A quote:

"Only as a person’s knowledge base increases do they grasp the concept of their own ignorance. Limited vision obstructs the view of the horizon."

Or, put simply:

"The less you know, the more you think you do"

Matt_75

IMO, based on just this forum alone and then not mention all the people who don't come here and misdiagnose it, I would say it is fairly common.

ezone could probably give you a more accurate answer since he's a dealer tech.

ezone

Every bad one I see is bad.
No more, no less.

Matt_75

I think he was looking for more of a "yes this is a common problem/occurrence" or "no not to many civics in the this generation have this issue."

ezone

I was trying to make a point.
Fine then.
I'm not the one to ask though. I only deal with the bad ones, and there are far more good ones than bad ones.
I think it is common, but I really have no clue what sort of percentage of the fleet has these issues.


I also diagnose far more than I get to fix.

BlueEM2

iTrader: (1)

^ Because stealerships charge too much

ezone

Many people are blinded by their own mindset.

Matt_75

Wait, so you're saying you diagnose the HG needs to be replaced and the customer says no thanks, I'll just live with it?

ezone

Or they go price shop now that they know what's wrong.........or they go somewhere else and try again, and get a parts cannon fired at it, sensors, thermostat, all that neat stuff just like you read in the shopping lists here.

ttl

So HG is replaced and runs like a dream so far. I'm a happy camper again..lol Fingers crossed!!
Actually My Honda dealership doesn't charge more than any other shop for certain jobs. ie: Timing belt replacement $310, oil change $46 but some jobs they do charge more, for some reason.
My next project....my rocking chair drivers seat, another fairly common issue...lol Cheers!!!

TreeFortRichard

It wouldn't surprise me to find it was all just the stuck open thermostat...causes zero heat at idle on civics...

Matt_75

Really...wouldn't surprise you? So a car with a stuck open thermostat that takes longer than normal to warm up could be causing all the symptoms he's experienced?

I think you should educate yourself on this vehicle before making a statement like you made. I'll go ahead and put you in the clueless category on this particular generation of civic.

ttl

I had the thermostat changed, as well as rad cap. Neither of which helped. The coolant was being pushed into the reservoir tank from the motor, after heating up the engine. This was because of exhaust gases being pushed into the cooling system thru the bad hg. So I had to keep removing this extra antifreeze from the reservoir tank and putting it back into the rad when the engine was cool, or else the rad would eventually become too empty and motor would overheat. Plus the reservoir tank would overflow if not emptied before it got to the top.
Still sound like a thermostat?