Sigma Overheating.... Ahhhh!

[H8DAG8]

I'm going to throw another wild guess at ya.

Have u checked the heater radiator under the dash? Or at least bypass it for testing.

Also, isn't there a head gasket that blocks a water jacket if the wrong one is used?

Hmm, haven't checked the heater radiator under the dash. And I'm sure the mechanics who put the head on would have checked the gasket, he was after all a 4g63 "expert".
And, both of those would cause overheating but that doesn't explain the bottom cold hose does it? If the radiator is flowing fine and the thermostat is fine - does that only leave the waterpump causing the lack of circulation? The waterpump is new but maybe it has (for some reason) sh*t itself?

Giving the guy who did the head and de-balancing work in an hour or so when they're open will post up what he says.

[H8DAG8]

Rang the guy -- like I thought he tried to make it everyone elses fault but his own. Said that they would happily look at it but if it proved to be something that wasn't their fault or a faulty product I bought through them then I'd be coughing up the bill -- knowing their prices.. I don't think so!

Ok, fired her up just before, radiator cap off, ran for a solid 20-25 minutes with the heater on full.
Got up to half temp on gauge after about 10-15 minutes, left it running for another 10ish minutes and the temp stayed as is (WTF!), checked to see the flow inside the radiator and for the life of me I couldn't see it flowing left (as it should? apparently?), to me it looked like it was just swirling slowly. Bottom radiator hose stayed stone cold, bottom tank stayed stone cold, top tank went hot-hot as did the top hose, water was steaming too but not boiling.

How obvious is the flow normally? I've got top-bottom tanks not left-right. Top hose is on right side bottom hose on left. So it should flow left -- yes? Didn't look like it to me, looked like a slight swirl in a clockwise motion - video'd it but too hard to with the sun glare etc.

I don't get how this works.. it looks like there is no flow inside the radiator, or minimal and it looks like a swirl. The bottom hose stays cold. The bottom tank stays cold. The top tank and hose get hot. The water gets hot and has a light steam. Sounds like no circulation, BUT the radiator was fine in the flow test (with a few semi-blocked water tunnels he guessed as it didn't spurt out QUITE as far as other ones did), and the car stayed at half temp.. so surely the water is cooling it down? WTF?

I haven't changed anything since the temp on the gauge shot up to 3/4 or just passed the other week except taking the radiator and thermostat out to get tested. They are now back in and this morning the temp gauge didn't get that high but the bottom hose and tank remained cold.

No one has heard of this before? This is driving me crazy! I don't want to take it back to the place that did the new head work (and belts, debalancing, tensioners, waterpump, frost plugs etc.) as knowing my luck they'll somehow prove it wasn't their "fault" and I don't have the money to fork out for their rip-off labour prices at the moment.

Someone pleeeeease help

Cheers

EDIT: Forgot to say that with the cap off with the car cold and at full temp when I squeezed the bottom hose in and out the water level in the radiator did fluctuate -- doesn't that show that there is no block? And that water must be flowing through the bottom hose? But then how is it still cold along with the bottom tank? My radiator can't be THAT good, and the guy radiator specialist said it looked like a few columns were blocked but nothing major so it's not operating at absolute FULL capacity but still... stumped... ready to drive it off a cliff...

[mstrrab1992]

Dude sell ur car u have a gremlin! Lol. Odddd......

[H8DAG8]

Dude sell ur car u have a gremlin! Lol. Odddd......

Lol trust me mate I'm tempted.. but when you take this:



to this:



it's a little hard. And I wouldn't get stuff all with an un-diagnosed (sometimes) overheating issue.

[mstrrab1992]

I see where ur coming from, if u were in aus i wuda made a road trip to come help, but it is a hard one, disconnect the heater box under the dash (well u do it from under the bonnet),rules that out, take thermo stat out, rules that out, i kow this sounds crazy, buy a few litres of coke, fill the radiator up, shake it, and if it is partially blocked the cokes acidity will get rid of some, then flush it good with water, ive done it before, then it rules that out, id take the temp sender out and hit it a few times on the wall give it ajolt rule it out, i wudnt reckon shoving coke in the engine but just put ur radiator on, connect bottom hose, take off top, get water hose shove in top hose and flush it like that, see if u get good amount of water flow through the top of radiator where uve disconnecged top hose leave cap on. Rules that out.. Hmm

[H8DAG8]

I see where ur coming from, if u were in aus i wuda made a road trip to come help, but it is a hard one, disconnect the heater box under the dash (well u do it from under the bonnet),rules that out, take thermo stat out, rules that out, i kow this sounds crazy, buy a few litres of coke, fill the radiator up, shake it, and if it is partially blocked the cokes acidity will get rid of some, then flush it good with water, ive done it before, then it rules that out, id take the temp sender out and hit it a few times on the wall give it ajolt rule it out, i wudnt reckon shoving coke in the engine but just put ur radiator on, connect bottom hose, take off top, get water hose shove in top hose and flush it like that, see if u get good amount of water flow through the top of radiator where uve disconnecged top hose leave cap on. Rules that out.. Hmm

I'll be taking the thermostat out soon when the car has cooled down and then see if the bottom hose heats up then (don't have any coke!)
Temp sensor/sender unit is brand new so should be fine, banging it on a hard surface -- what does this do? Can it damage/break it by any chance if I do it too hard?
When you say connect bottom hose of radiator to engine, and take the top one off to put a hose in there -- what do you mean? You say put the hose in where the top inlet is on the radiator and see if I get a good amount of water flow through the top of the radiator -- how do I see this if the cap is on? Do you mean leave the cap off?

[mstrrab1992]

Buy coke:O!

if u do it to hard it may break, just to give it a little jolt to see if anythings playing up, even if u get a spanner and tap it lightly.
ok say you have the radiator in the car, hooked up as normal, all u need to do is take the hose from the top of the radiator off so the top of the radiator has no hose, but the hose runs into the thermostat housing, then get ur garden hose and put it into the radiator hose that runs into the thermostat housing (make sure the thermostat is out) then see if u get a good amount of water to flow through the engine and out the top of the radiator, leave the radiator cap on.

[mstrrab1992]

U say its a new temp sender, if it was replaced, then u noticed the temp gauge is higher then usual, it could be the temp sender for the engine, but not for the dash, so say if the dash is a 30 ohm receiver, then the temp sender would have to be a 30 ohm sender, but if its a 50 ohm sender then it'll be reading hotter then it actually is, it could have had a temperature sender suited for the dash before but now its been changed to the one for the engine, but not to match the dash? it could be giving you a false reading..

[H8DAG8]

Buy coke:O!

if u do it to hard it may break, just to give it a little jolt to see if anythings playing up, even if u get a spanner and tap it lightly.
ok say you have the radiator in the car, hooked up as normal, all u need to do is take the hose from the top of the radiator off so the top of the radiator has no hose, but the hose runs into the thermostat housing, then get ur garden hose and put it into the radiator hose that runs into the thermostat housing (make sure the thermostat is out) then see if u get a good amount of water to flow through the engine and out the top of the radiator, leave the radiator cap on.

Ah ok I get you now. Shouldn't I check for flow the other way though? Put it in the hose going in the top and see if it comes back out where the thermostat goes? Could try both ways I suppose? Funny thing is, I just went out and put a long screw driver on the thermostat housing and put my ear on the end, gave the bottom hose a squeeze and I can hear that little loose diddly-dad thing on the thermostat moving.... so that MUST mean that it's flowing fine through the engine? As when I squeeze the top one it makes the same sound but quieter..

U say its a new temp sender, if it was replaced, then u noticed the temp gauge is higher then usual, it could be the temp sender for the engine, but not for the dash, so say if the dash is a 30 ohm receiver, then the temp sender would have to be a 30 ohm sender, but if its a 50 ohm sender then it'll be reading hotter then it actually is, it could have had a temperature sender suited for the dash before but now its been changed to the one for the engine, but not to match the dash? it could be giving you a false reading..

Correct new temp sender unit. I've had so much going on the last month or so that I can't actually remember why I changed the temp sender unit but I'd say it was because the issue with the temp goin above half then back down to half started back then. I got a new one because I was trying to fix that. How would I find out what ohm my sender is and what ohm the dash gauge is?

EDIT: Third post in this thread http://www.sigma-galant.com/viewtopic.php?f=30&t=7721 shows the difference in temp senders. I remember repco didn't list one for my car as they don't even list 4g63's for my car.. so this is what they got me from an L200 or L300 I think it was.. said that it wouldn't matter.. ?

This is the little metal loose do-dad bit I can hear when squeezing bottom hose:

[H8DAG8]

Ok just let all the water out, took thermostat out, top hose off, and water flowed fine through the radiator and engine and back out the thermostat housing.
Boy don't I love wasting coolant, not gonna buy another bottle until she's sorted lol just water will have to do.
See video here: http://www.youtube.com/watch?v=-iDcLJ5JFDY

Going to leave thermostat out, fill her up with plain water, fire it up and see how that bottom hose feels after 15-20 min's of idle.

[mstrrab1992]

Yeah good idea about the coolant shoulda mention to get a clean bucket or something and then drain it into that then just use water, it looks to be flowing fine, all i could think of now is the temp sender not matching the dash, as for the tools to check what ohm the dash reads im not 100% sure where ud get some, maybe an auto elect? my 1974 lancer has overheated at half on the dash, and its got a 2.6 astron in it.

[H8DAG8]

Just took thermostat out, hooked everything back up, filler her up with water, and after 5-8mins the bottom hose was WARM!!! Bottom tank was getting hot, and with radiator cap off water was very turbulent in comparison to when the thermostat was in and it was over half temp before!!!

Thermostat in, at just over half temp: Water seems to be swirling very VERY slowly, and random.
Thermostat out: Water flowed very well and was moving 100x faster compared to with thermostat in at over half temp. Looked to be flowing right to left but bit hard to tell as car shakes a bit (due to lumpy cam) and it was moving so fast it was hard to tell which way it was going, definitely moving though!

So.. must mean the thermostat yes? But the bloody thing is brand new, and it's the second brand new one I've had. What the hell does that mean? I tested it and it did definitely open in the pot on the stove (suspended) but seems like it's not (or bearly) opening in the car..

Idea's?

PS thanks everyone for their help so far, much appreciated.

[mstrrab1992]

i first said take it out >_<! and new items cant always be faulty, it may be the wrong thermostat, not opening at the right temp, it may be for a 2.6L instead of a 2L, cuz the 2.6's get hotter, it'd open the thermostat more, since the 2l isnt getting AS hot, it'd open a lil of the way but not all the way.

[mstrrab1992]

permanent fix = leave thermostat out!

[H8DAG8]

I know you said that before but because I'd taken it out and tested it I assumed the (idiots) at Repco wouldn't have given me the wrong one.. twice..
So how do I make sure I'm getting the right one now!?

permanent fix = leave thermostat out!

Haha yea I'll pass on that

[mstrrab1992]

left mine out >_>.

hmm just go in and tell them, the thermostat isnt opening all the way when the cars hot and tell em that they gave u the one thats in it. :S

leaving the thermostat out wont hurt the car, it just means it will take a little longer to warm up.

[l3004x4drifta]

...by the way mate, good job with the sigma! very tidy!! and just to clarify, when you took the thermostat out and ran it and the bottom hose did become warm, what was the gauge reading? i think you should take it for a good drive and see how it goes. just make sure all those clips and bolts are tightened but good. ha! goodluck

[H8DAG8]

left mine out >_>.

hmm just go in and tell them, the thermostat isnt opening all the way when the cars hot and tell em that they gave u the one thats in it. :S

leaving the thermostat out wont hurt the car, it just means it will take a little longer to warm up.

Yea I don't trust them anymore haha will have a talk to them tomorrow.
As for leaving it out, I can't remember who told me but it was a while ago and they said running no thermostat short-term is ok, but long-term it can damage the engine -- something about the engine is made to get to a certain temp within a certain time period and extending this time period and decreasing the temp for so long affects something? I dunno.. I'd just rather run one, they put it in there for a reason (I hope)

...by the way mate, good job with the sigma! very tidy!! and just to clarify, when you took the thermostat out and ran it and the bottom hose did become warm, what was the gauge reading? i think you should take it for a good drive and see how it goes. just make sure all those clips and bolts are tightened but good. ha! goodluck

Haha cheers mate, pride and joy, just about over it though lol, unless I find a small block lexus v8 for it - then that's a different story
When the bottom hose became warm and the bottom tank got hot it had only been running for say 5-8minutes, the car wasn't stone cold though as I've been fiddeling and starting it up a few times throughout the day trying to fix it. The gauge was still very very low, just above cold - is that good or bad?

[l3004x4drifta]

sounds pretty good to me! what do you reckon? take it for a spin and just keep an eye on things. no thermostat is fine. go on, do it already!!

[robbert]

I don't think it's flowing. The water must be stagnant, getting hot and the hot water is rising.

I would bypass heater, remove thermostat, I would even empty the water, put a litre in and start it, slowly adding more water until full ( to avoid an air pocket.) It should be splashing around at the radiator cap.

Also check your hoses. Some have a wire coil in them to stop them sucking in. They rust out and could cause a blockage or restriction. Just squeeze your hoses to feel for a crunching sound. And check the smaller hoses. Pull them off and look through them. (manifold ones I think)

[H8DAG8]

Haha no time now unforunately, will put all the nuts and bolts back on and take it for a spin tomorrow. Might bleed it again first. Thermostat out.
Anyone on here know the specific part number for the thermostat I need? Or have a location of where I can find the part number? Supercheap and Repco seem to be useless at finding me the parts I need for my car.

[H8DAG8]

I don't think it's flowing. The water must be stagnant, getting hot and the hot water is rising.

I would bypass heater, remove thermostat, I would even empty the water, put a litre in and start it, slowly adding more water until full ( to avoid an air pocket.) It should be splashing around at the radiator cap.

Also check your hoses. Some have a wire coil in them to stop them sucking in. They rust out and could cause a blockage or restriction. Just squeeze your hoses to feel for a crunching sound. And check the smaller hoses. Pull them off and look through them. (manifold ones I think)

Don't think it's flowing? With the thermostat out the water was definitely flowing and bouncing about. Hoses are good, no cracks or wear and tear on them, they are relatively new. And with the thermostat out and the garden hose in the top radiator hose the water flowed good and well both ways through the engine and radiator.. why do you say it's not flowing and must be stagnant? Or are you referring to BEFORE the thermostat was out? If that's the case then yea that's sounds about right, the thermostat was staying closed or bearly opening, and the hot water was rising in the radiator and the cold water dropping down hence the cool lower hose and tank and hot upper hose and tank. Yes?

[H8DAG8]

Just took it for a 25-30minute drive and the bastard wouldn't get off cold! Or a fraction above it.
Surely it's bad for an engine to stay that cold for so long? Otherwise what's the point in thermostats?

[mstrrab1992]

Engines perform best at cold temps ive never encountered an engine failing due to coldness?? Dads 45 and has never run thermostats in his old cars, not 1 problem yet

[mstrrab1992]

Thermostats just let the engine warm up before use

[mstrrab1992]

Warm up quicker

[geezer101]

Looked like your new thermostat was a dud. Get another one (while you're there have a look in their parts catalog to see what the difference is between other mitsu thermostats of your engine type - temp ratings, size of flow valves etc) It won't kill you engine to have it running cold but it won't run properly either. Same old story, just takes one stupid thing...

[H8DAG8]

Just rang mitsi, they have none in NZ, asked them for the part number -- wouldn't give it to me (wankers). Asked for the temp rating and he said 82 degrees, and that's what my one has stamped on it, WTF?! Surely this one can't be a dudd, if it is it's the second one in a row that's a dudd surely that can't be right.

I thought running no thermostat meant way cooler engine for longer meaning rings didn't expand to where they should be sometimes chewing oil? And using more fuel because the car's running cooler? And it wears something out can't remember what it was. Plus on cold winter mornings I wouldn't be able to de-fog the front and rear windows as the blower wouldn't have hot air coming out.

Seriously over this shite now

EDIT: I'm just thinking, maybe it's the right temp rating but the flow isn't large enough? Would having the wrong flow rating/size make that much of a difference? I mean the thermostat can't be faulty as it opened up fine in the pot (granted I didn't have a thermometer in there but surely it was correct), so doesn't that only leave the flow if it ran fine without the thermostat? Wouldn't have thought the variations in flow would be that major? Will call repco tomorrow and see how many different ones they list for my engine.

[mstrrab1992]

Go into repco demand for a replacement, hope for the best

[H8DAG8]

Just rang them. If I don't have a box they can't replace it, f*ckin wankers excuse my french.
Said there are 2 variants for my engine, assholes didn't tell me that the 2 other times I've been there to get one.
Both 82 degrees one is 52mm one is 64mm. Thing is, that must be the overall size as mine measures 52mm overall, so a 64mm won't fit in there as this one is the perfect size.

Again, WTF!