Maruti 800 Overheating Problem


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Dear friends,
There are various reasons of overheating but lets first know about the components and working of the cooling system.

The cooling system consists of the radiator, radiator cap, radiator fan, hoses, the degas tank, coolant and in the engine side the water pump, water pump pulley, the thermostat valve and the water channels to flow the coolant in the engine.
The electronic components are the fan control thermostat, ECT sesnor(forMPFI) fan relay, and the temperature sensor which is connected to the temperature meter, and the temp meter itself.

1. Coolant Flow
The coolant is flown continuously by the water pump which is driven through a pulley and belt. (Check the pulley and the condition of the belt also check for any slippage or tightness in water pump rotation)
The coolant flows through the engine, intake manifold and the head. (If the car has heater option, the coolant goes to the small core in the cabin too.) The head gasket prevents any compression, oil or coolant leak while the engine is in operation. (Check the head gasket that if its blown/deteriorated this will cause oil-coolant mix and heat the car also this will lead to compression loss ) I suffered oil leaks from the head gasket as the head was in bad condition and I used it after lathe work, later I replaced with different head.
The coolant then flows to the radiator which is then cooled by forced air from fan and then again is sent towards the engine.

2. Radiator
(There are two types of radiator aluminum and copper. The copper radiator is repairable and does not burst under high pressure but it takes time to cool down. The aluminum radiator is a bit tough to repair but its advantage over copper is that it cools down faster. The radiator cap also plays a major role here) as it builds up and keeps a constant pressure in the radiator which prevents the water from boiling. The excess water/pressure is transferred to the degas tank through the thin pipe, the pressure releases from the small hole in degas tank cap and water goes in the tank which is again sucked back in rad when the pressure decreases in radiator. Check the radiator cap spring and the rubbers for corrosion. Many mechanics do remove the rubber Also check the degas tank for any cracks or leaks.

3. Thermostat Valve
The role of the thermostat valve is to restrict coolant flow during cold start so that the engine can attain minimum operating temperature. after the engine reaches that stage, the valve opens and coolant flow starts.
Many a times the valve is clogged due to impurities in water thus restricting flow. This thing can be removed and will not harm the engine.

4. The electronic components
a. There are two types of fans 80W and 120W for AC models, with time the fan bearing may tighten or lose too much which may cause loud noise from fan or tighter thus slower fan movement. Check fan movement and compare with other M800s fans
b. The electronic thermostat which turns the fan on/off. This may become faulty by aging and may cause delayed start of fan thus causing heating A direct bypass switch can be connected to the relay so that fan can be started when we see temp rise and fan is not working. or else change the thermostat with only MGP or Minda Thermostat. For the MPFI models the ECT sensor sends signal to the ECM to start the fan. In emergency cases if the ECT sensor connector is removed, the fan starts automatically.
c. The temperature sensor for the meter or the meter itself fails rarely but can fail.
d. If the fan relay is old the contacts or terminals may have corroded thus giving less power to fan. Also faulty alternator or low charged battery may be a cause for slow fan. Thus all these need to be checked.

5. Cleaning
The cooling system including the radiator must be cleaned thoroughly. The engine side should be cleaned using pressurized water pipe inserted in one hose and observing the water coming out of bottom hose for any head gasket or metal chips.
The copper radiator can be cleaned by professionals using acid. Then using tweezers all the fins need to be straighten for maximizing air flow (this requires lots n lots of patience)
All hoses should be inspected for any cracks and then cleaned from inside. the thin degas tank hose is many a times neglected. The degas tank should also be cleaned using soapy water and all dirt inside should be removed. (Do not forget to remove all soap deposits from inside the tank)

USE ONLY DISTILLED WATER AND COOLANT MIXTURE. As the normal tap water's impurities cause the water to boil.

There are few more things which will be covered later . . .
Very nicely written and very detailed. This covers almost everything.
 
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Maruti 800 overheating issues

Hi friends
My maruti 800:2008:model mpfi .my car sometime can't start after ride.but no issues in morning.so I went work shop . techinitions cleaned radiator and changed fan .now engine overheating after 10-30 minutes.i check fan .it's working.engine oil and coolant is fine.same time accelator continue working.i went lot of workers.but still compliant pending.so please advice me.
Before one techinitions said me starting issues for fuel pump.battery very good condition.
 
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Re: Maruti 800 overheating issues

Hi friends
techinitions cleaned radiator and changed fan .now engine overheating after 10-30 minutes.i check fan .it's working.engine oil and coolant is fine.
I'm taking a guess that the engine oil is relatively new. I'm also guessing that the technicians have checked for hose damages, belt breakages etc. Coolant level alone is not enough. You have to watch out for coolant concentration too. Fuel pump does not have any relation with the cooling system. May be they're referring to the coolant pump. If that one has a bad impeller or other worn out components, the engine may overheat. Other things to check are blockages in the coolant passage. Cleaning the radiator fins is different and won't solve the problem if the tubes carrying the coolant have blocks. One more important thing to check is the thermostat. Hope you get the issue sorted out soon[:)]
 
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Maruti 800 has been phased out. My radiator is leaking. The garage has not been able to source a radiator, and the top hose and bottom metal pipe to repair it. Any idea where I could get it in Mumbai. Are these parts still available?
 
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i faced the same issue on last Wednesday. My car was with ABT regular services. Recently they cleaned radiator and changed couple of components like spark plugs, cables, electric condencer and all for engine choking problem.
1. i told them it over heats after 100 kms.. they said its normal.
2. i complaint when i put AC, it choks like anything.. car dont move.. they said it wont happen again we changed all spark plug and fuel system is clean.
3. it wont start in morning some time. i need to keep the idle for 2 mins then the car settle down. then i can use AC on 4th gear. These ABT guys keep concentrating on looting money and no solution no Gyan to the issue reported.
4. this week i hope i serviced it 3 months back so there will be no issues so started to home town.. without AC.. after 50 km engine went to full heat white smoke from silencer
i stopped the car within seconds and found the radiator water blown all over the engine bay.. over flow tank cap blown off too. coolant turned amber color. this is the new coolant filled 3 months before.
5. i got toed up by sriperumbudur Rajalakshmi maruti showroom.. they keep the car now.
6. They changed radiator, still the water came up with air bubbles in radiator. they declared its a head gasket problem.
7. they asking for 16k for over all clean up.
8. Any thought in knowing the cost for head gascut job ?
 
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Head Gasket costs between 200 and 1000 rs as per the brand you want to have , easily available. if you are a diy guy then with the modest tools like 1. rachet 1/4 inch set and some 8, 10, 12 spanner it can be done without any major cost.

you can get it done from a good engine mechanic (find a place where engine boring and head work is done ) at these places it may cost as little as 1000 to 2000 to change the head gasket only if any other problem is there it may need more.
 
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thanks for response.
i changed all those recommended by MAS guys. White smoke is gone.
now engine bursts when raising. they said silencer gone bad it stuck the smoke out.
am looking for a silencer.. MAS said its 9.5k. when i enquire out side its 2k.
height of ripping of poor customers!!! worst Maruti service mafias..
 
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Dear i maintain my maruti my self as no good mechanic is ready to spend his time on it and alos the mass charges high.
Basically the maruti 800 is a very simple vehicle and if tuned correctly may last long without any major spending on the maintenance.
kindly check the steel type silencers available in aftermarket it may cost around 2000 they do not rust easily as chennai is humid. (normal replacement iron alloy silencers for 800 are available around 1100 here in mumbai)
 
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thanks for your advice.
i went to MSM.. they found its not a Silencer issue. its an issue with tuning. timing belt was replaced by Rajalakshmi cars, sriperumbudur. they didnt tune it properly and blaming silencer. More ever MSM said Silences is only 2500. dont know why Rajalakshmi quoted me 9500 for full piece.

1. after tuning timing, the blasting sound from engine was arrested. it was nice.
2. but no pick up at 2, 3rd gears. i left the car there in MSM for 4 days for diagnostics.
3. took their time to troubleshoot and found the fuel pump went weak. the PSI output is not sufficient to petrol flow. changed fuel pump for Rs 6700/-
4. it worked well, now its pulling even in low gears with AC.. engine is not slowing down.
5. proper diagnostics was missing with Rajalakshmi, they simply focused on Ripping customer to reach their monthly targets.
now the major issue in my car is the AC cooling. its good in the evening.. but during day time there is no feeling that the AC is running. never get cool. AC was recently checked and serviced 2015. removed the dash and clean the dust off. Replaced condenser, GAS filled in. i dont know whats wrong now. i think just filling GAS will not fix problem. pls suggest... how to check the AC relay.. thats the only known thing to me which may gone faulty.
 
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The Pickup is due to timing of the point condenser (point gap and angular timing) which should be set by dwell meter and timing light gun. after this if your engine is having good compression the maruti 800 should work fine with regard to pickup at various gears.

the fuel pump in an carburettor maruti is only 300rs or so , and most of time it is issue with cleaning of carburettor.

for MPFI maruti the fuel pump may be below 2500 and effects the pickup directly, for MPFI cars the Fuel injectors needs to clean as well as throttle body.

These are basics and you can study the car and gain knowledge about automobiles from this car easily.

The ac in maruti 800 is just not good enough for chennai heat , it will cool lightly, if ac is cooling ie cool air blowing from vent then the ac clutch is engaged and working fine.
You can check the pressure of inlet and outlet valve in the ac in running condition by using the ac manifold pressure gauge if gas is low you can fill it.

my advise if just cooling don't waste money on maruti 800 ac , it may not work well
 
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Silver Dove, you're right in most of the statements. i agree.
maintaining this with dealer based work shops is like opening our house gates for looters.
am not going to spend money on AC. Highway milage was 23km, now it hardly pull 19km, City mileage is also went down from 17km to 14km without AC. will keep this car till end of this year and sell off.

ive replaced almost all parts except the half engine. now the coolant is leaking from engine. this causing the car overheating when i drive inside city >30 km. dont have time to fix on own yet. its leaking from behind i think some screws are not tight or the new gasket is not placed properly.
silencers are not available here in Chennai. so they are looting.

The Pickup is due to timing of the point condenser (point gap and angular timing) which should be set by dwell meter and timing light gun. after this if your engine is having good compression the maruti 800 should work fine with regard to pickup at various gears.

the fuel pump in an carburettor maruti is only 300rs or so , and most of time it is issue with cleaning of carburettor.

for MPFI maruti the fuel pump may be below 2500 and effects the pickup directly, for MPFI cars the Fuel injectors needs to clean as well as throttle body.

These are basics and you can study the car and gain knowledge about automobiles from this car easily.

The ac in maruti 800 is just not good enough for chennai heat , it will cool lightly, if ac is cooling ie cool air blowing from vent then the ac clutch is engaged and working fine.
You can check the pressure of inlet and outlet valve in the ac in running condition by using the ac manifold pressure gauge if gas is low you can fill it.

my advise if just cooling don't waste money on maruti 800 ac , it may not work well
outer view of my car 14 yr old
 

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Dear All,

I using 2000 year Model maruti 800( 5 Speed ) car.Shall i change tubeless tyre for this model car?My nearby mechanic informed tubeless tyre not suitable for this old model cars. Pls suggest.
 
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Dear All,

I using 2000 year Model maruti 800( 5 Speed ) car.Shall i change tubeless tyre for this model car?My nearby mechanic informed tubeless tyre not suitable for this old model cars. Pls suggest.
The Mechanic gave you the wrong information. I have 1998 M - 800 Model with AC and have Bridgestone Radial Tyres with tubes, not a single puncture for 10 yrs and threads are in good condition. But considering the safety, I will be replacing this time with preferably Michelin Tubeless and may be 145/80R 12 instead of 145/70R 12 for better performance and grip. Also this fits in the dicky as confirmed by other TAI members. There is no need to change the stock Rims. The dealers sometimes try to sell Alloy Rims costing almost the cost of 4 Tyres.
 
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