Temperature Gauge 1998 1999 2000 2001 CG Accord Coupe

[HondaDreamerCG]

To be honest Scooby i dont kno what coolant was in it  , i bought the car 6 months ago , with a full honda history , upto 66k miles its now at 72k miles , im glad to hear others with the same model that have quick heat up times !!! (THANKYOU DAVEBRADS)  everything works perfectly and NEVER overheats , im just taking preventative measures to ensure the car treats me well Could you recommend a coolant for future reference ?

[Laird_Scooby]

If it was the previous gen i'd have no hesitation recommending ethylene glycol (blue or green) but yours is on the changeover of when the Japanese started using OAT coolant so it's tricky for me to be sure.

What colour is the coolant that's in it at the moment?

[HondaDreamerCG]

Looking into the bottle scooby , it looks like a dirty red/brown colour

 

Unless it was mixed with another color coolant to give this color

[Laird_Scooby]

Eek!!! That doesn't sound good! It sounds as if they've topped up ethylene glycol with OAT which could spell trouble.

Do you have the handbook for it at all? If so, have a look in the back at the "Fluids & Lubricants" section, howver they've disguised it and see what sort of antifreeze is recommended.

We can work out a plan from there!

[HondaDreamerCG]

Hi scooby , i searched that book inside out last night for the correct fluid (coolant) i should be using, could i find it i found some other very useful information .....but sadly nothing about fluids !!!! so again today i went to the radiator and lifted of the cap (the car had been idle a few hours ) and the coolant colour in the radiator is like an ultra violet green and the coolant in the expansion bottle is a dirty dark red colour . Does this sound right ? is the coolant in the radiator not meant to be the same colour as whats in the expansion bottle !!!

 

How long does it take for the 2 large fans to come on , i have rarley heard or seen them move !? i have read thru recent posts from hughzee he replaced a  "LAZY" fan switch on a honda oddessy !!???

[Laird_Scooby]

It should all be the same colour!

I'm trying to remember if yours is a sealed or semi-sealed cooling system, the difference being the expansion tank has one hose into it from (usually) just under the radiator cap and is meant to be half full or thereabouts, sometimes a little higher depending on the car.

Sealed systems are similar but generally have a large bore hose feeding back into the bottom hose somewhere and generally have either a radiator cap or screw cap on the expansion tank.

If it's the semi-sealed system, then it's probably functioning as it should and just has a dirty expansion bottle.

This pretty picture shows a semi-sealed system :

Obviously not a Honda (looks more like a Ford from the rocker cover! ) but if that is similar to the arrangement you've got then i would suggest disconnecting the small bore hose from the radiator (or expansion bottle), removing the expansion bottle, empty and clean it and then refit it, adding some ethylene glycol type antifreeze diluted 50/50 or if you're buying the "Ready to use" stuff, that's pre-diluted. Try and get the green stuff though so you don't get any strange colour mixes in your expansion bottle!

If on the other hand there is a drain hose from the bottom of the expansion tank into the engine or bottom hose and the tank is sealed with another radiator cap or screw cap rather than a cap similat to the screenwash cap then it's a sealed cooling system in which case we'll have to proceed slightly differently.

So far though, there's nothing that is worrying me, other than a dirty expansion bottle!

[Laird_Scooby]

Just remembered something so did a bit of digging :

That should be the arrangement you've got, that's for a 99 2.0 Accord Coupé so it's a semi-sealed system.

Remove cap 2 in the diagram, lift out the hose from the tank, remove the tank and empty then clean it. Soaking overnight in a tub full of boiling water and half a dozen extra-strong denture tablets works really well. Obviously give it a good rinse after but while it's soaking, preiodically give the tub a shale to agitate it and help loosen the dirt.

Refit then top up as described.

[HondaDreamerCG]

thanks scooby for doing a little digging , i too use honda lings ... i understand what your saying and im gonna wait for a dry spell to return in the coming days and remove the water bottle , let it soak , clean it then replace and refill with green ethylene glycol antifreeze , mixed or 50-50

 

Thanks will post snaps of progress

 

Thankyou

[Laird_Scooby]

Looking forward to the progress pics!

[Lumpy]

I've has a good skim through other posts but not found one the same, I am sure I'll be redirected if there is 🙂

3.0 v6 water temp gauge is stable as anything at all times except when stuck at idle for ages in traffic. The fan is kicking in and no actual issues found other than the gauge going from normal temp, just under halfway on the gauge, to the red line in about 5 seconds or less. I quick rev on the engine brings this down again in a few seconds but it is disconcerting to say the least to see it flying up the scale 🙂

There appears to be no air in the system and the levels are spot on with no water loss but I am guessing it's air under the sensor giving false reading as there is no issue at any other time. Is it worthwhile to loosen the sensor and bleed from there in case? I could just change the sensor but there appears to be not much wrong with it at any other time. I have a short vid from earlier but seems pointless posting it. As soon as the revs are  >1000rpm the temp drops on the gauge as quick as it goes up.

What say the collective knowledge databasers. TIA

[Laird_Scooby]

When did it last have a timing belt, water pump and what's the mileage now?

It sounds as if the water pump is getting lazy and/or failing as the fan seems to follow the lead of the temperature gauge.

[Lumpy]

Not sure when the pump was changed, I've only done 12k in her. Cambelt done 25k ago according to previous owner.

Cooling fan kicks in and out as you would expect but not in relative time to temperature gauge reading.

I had thought about lazy pump but the temperature goes from normal to red in just a few seconds. I know my Honda 1100 and 1200 bike engines need a little blip when the temperature gauge creeps up due to impeller being inefficient at tickover.

[PTR200S]

I would think lazy pump too, either from the belt drive being slack or the impeller in the pump getting on a bit / corroded?

Or the beginning of pump bearing seizure ? . Bearing tightening up slowly ? Was the pump changed with the belt???

Have you got a temperature "laser" gun?  Can you check the area around sensor to see if it is lower than say the rad or pipe temperature..might give some clues and point to an airlock but then you need to know why has it developed an air bubble...leakage maybe? , pump, pipe connectors or the favorite the radiator, lower hose , clip.

[Laird_Scooby]

18 minutes ago, Lumpy said:

Not sure when the pump was changed, I've only done 12k in her. Cambelt done 25k ago according to previous owner.

 

31 minutes ago, Laird_Scooby said:

What's the mileage now?

If the PO didn't change the water pump, there's every chance it's on it's way out. On the C-Series engiens, the timing belt interval is 96k miles but the water pump then needs changing at 120k because it wears out. Wise owners change the water pump at the same time as the timing belt, especially as it gives further peace of mind. If the PO skimped the water pump, that could well be your problem.

I'm fairly sure the timing belt interval on the J-Series is the same as the C and if so, suspect the water pump is on its last legs. Usually they start leaking and the first sign of that is a drip from the crank pulley. They're designed to do that as an indication they need looking at. I've known of a water pump to throw its bearings a week after starting to leak and one extgreme case where it lasted 7 miles from starting to leak.

The new owner wasn't happy after buying it 7 miles previously! It threw the timing belt with predictable results.

 

Forgot to mention, the fan won't exactly follow the temp gauge, the switches (i can't remember the exact figures so these are examples) are something like 96-92C and to explain that, they switch on at 96C but don't switch off again until the temperature has dropped to 92C so the fan will stay on longer when the gauge is coming down than when it first switches on. THat doesn't quite make sense but i hope you get my meaning!

[Lumpy]

It makes sense, she needs a service soon and MoT in April I think so I will get new belt and waterpump done. There is definitely no leaking of coolant yet and no drip from the pump thankfully. Does the impeller erode?

[Laird_Scooby]

All the usual problems apply to the water pump, impeller erosion, bearings and seals fail and the impeller can become loose on the shaft.

However, how many of those and in what level they apply to the J series water pump i'm not certain. Usually if they are changed at the same time as the timing belt there isn't a problem with them so it's difficult to say. I'd keep an eye on it though between now and when you do it.

[Lumpy]

cheers. It only EVER does it when idling for a long time, thankfully. Was much more of a concern the first time it did it 🙂

[hughezee]

Could be a sticky thermostat and radiator, not cooling efectively, I would recommend a new stat and flushing the cooling system. Dave and Pete could be spot on with their predictions of water pump issues, but assuming its the original pump unless it's making a noise or leaking its likely fine, although I would still consider a new pump at some point though.

As pictured above another area to consider is the EGR system could be clogged up or it has an up and coming complaint is the temp sensor for the display is located very close to this area and if the valve is lazy or sticking temperature fluctuations will happen especially when at idle.

The picture above is from the ECR passage completely blocked which gave temperature-related niggles.

 

[Laird_Scooby]

3 minutes ago, hughezee said:

I would recommend a new stat and flushing the cooling system.

I thought of suggesting that as well Stu but didn't because i figured it would more likely show it's problems on a fast run rather than prolonged idling.

I didn't realise the temp gauge sensor was so near the EGR tract on the J series, sounds like it could be a good idea to check that first!

[Lumpy]

9 hours ago, hughezee said:

Could be a sticky thermostat and radiator, not cooling effectively, I would recommend a new stat and flushing the cooling system. Dave and Pete could be spot on with their predictions of water pump issues, but assuming its the original pump unless it's making a noise or leaking its likely fine, although I would still consider a new pump at some point though.

 

I would only say, logically, the radiator and fan combination is pretty much spot on as when the engine is revved slightly the temperature drops to normal quickly on the gauge and when starting to drive again the temperature drops to normal in seconds and stays there. In the past, a dodgy radiator take a fair while to drag the temperature back down even when driving.

Great response and gives me something to look at.

[hughezee]

12 hours ago, Lumpy said:

the engine is revved slightly the temperature drops to normal quickly

I would think a thermostat or a clogged radiator cap valve, the increased pressure from the water pump aiding the cooling, as fan speed is not affected by using the loud pedal, either way, hope you get it solved before the warmer months... 👍

[PaulS]

I would definitely have a good look at the thermostat....and ideally replace it anyway as they are cheap but unexpected failure can be very costly  - as I know from personal experience.... I would even consider removing it completely if you cannot easily replace it, but doing that will cause your car to run cool with another lot of attendant issues....

Another car of mine had a thermostat which suddenly and without any warning stuck shut at a motorway lunch stop on the German autobahn a couple of years back and as I was not watching water temp, the first thing I noticed whilst driving some 20 miles further down the autobahn was low oil pressure - water temp showed normal!....  Despite pulling over almost immediately, the excess water pressure had popped a core plug and dumped the coolant; the low oil pressure was due to my now denatured oil trying its best to cool and lubricate. result was a cracked head and engine out / strip to inspect for other damage.  Needless to say really, when I rang teh ADAC for help they thought I was barmy telling them that I had lost a core plug in the middle of summer!  But they believed me when the ADAC guy poured water into the rad and watched it pour out of the side of the engine!

[Lumpy]

I think the stat is ok, and the rad cooling is okay too as logically if either were poor the temperature gauge wouldn't return to normal in less than 5 seconds if the engine is revved to just over 1000 rpm, that aside, maybe a pump and belt change combined with stat change is a good preventive measure so all comments are appreciated.

On a negative side, I may have to let the Coupe go, very reluctantly, as the wife is really struggling to get in and out, her parent (old farts) can't even get in the back (bonus) so on the lookout for an accord v6 saloon or estate. If I can I will keep both of course 🙂

[Laird_Scooby]

53 minutes ago, Lumpy said:

on the lookout for a Legend V6.

Edited for UKDM availability. ^^^^^

There are a couple of 3.0 V6 saloons sedans round my neck of the woods, a white one and a gold one but the handlebars are on the wrong side.

Unless something has sneaked under my radar, the only UK market V6 Accord was the Coupe in the generation you have.

That means the closest "living relative" with 4 doors in the UK is going to be the Legend. The other option is an Elysion like Pete's got but that's an import.

Do you mind me asking what the nature of your wifes struggling is?

[Lumpy]

1 hour ago, Laird_Scooby said:

do you mind me asking what the nature of your wifes struggling is?

not at all. She has a partial knee replacement on her right leg and now the bit that wasn't replaced is causing a lot of grief. The opposite hip has been replaced so there is no muscle at the top of the left leg compounding the issue. The strain of climbing down into the coupe and out of it too is getting very difficult for her.