Low compression and high fuel consumption
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Re: Low compression and high fuel consumption
No it's not drain I'm talking about. Without a thermostat your coolant system is always open. Making the car need to keep itself a lot warmer... You don't seem to understand what people are saying to you.
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Re: Low compression and high fuel consumption
Yeah sorry I'm still a new for these mechanical stuff... Previous owners may have removed the thermostat as a shortcut solution for the overheating on high rpms. My mechanic couldn't identify the reason for the overheatingYorindesarin wrote: ↑Sat Nov 14, 2020 4:17 pmNo it's not drain I'm talking about. Without a thermostat your coolant system is always open. Making the car need to keep itself a lot warmer... You don't seem to understand what people are saying to you.
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Re: Low compression and high fuel consumption
OK this image may help as to why you should never just remove the thermostat ( on most engines)
as you can see if the stat is not there at all then you will be losing some flow from the pump back down the bypass, instead of going through the rad
if you don't have one then get a new one in there right away
as you can see if the stat is not there at all then you will be losing some flow from the pump back down the bypass, instead of going through the rad
if you don't have one then get a new one in there right away
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Last edited by 350matt on Sat Nov 14, 2020 10:09 pm, edited 1 time in total.
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Re: Low compression and high fuel consumption
Is fuel in Sri Lanka sold in US or Imperial Gallons?
8 mpg (US) = 9.6mpg(UK)
8 mpg (US) = 9.6mpg(UK)
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Re: Low compression and high fuel consumption
Here we use litres and kilometres. My car is doing only 3.x kilometres from a little
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Re: Low compression and high fuel consumption
A silly question maybe , but could your climate be a reason for removing the thermostat?
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Re: Low compression and high fuel consumption
Without the thermostat the engine will take longer to warm up and will use more fuel. Then once up to temperature the coolant circulation will be less efficient for the reasons posted above.
As a first job fit a thermostat and see what effect that has.
As a first job fit a thermostat and see what effect that has.
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Re: Low compression and high fuel consumption
Yeah that's possible. But my one has an overheating problem when doing high rpms which other cars don't havegoodeggbob wrote: ↑Sun Nov 15, 2020 8:21 amA silly question maybe , but could your climate be a reason for removing the thermostat?
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Re: Low compression and high fuel consumption
I suspect that the thermostat was removed because the car had an overheating problem and someone thought that might fix, or at least mask, it. This was never going to work, for the reasons Chris says above.
You need to replace the thermostat and then work out why the engine is overheating in the first place.
It might be a problem with the coolant flow; blocked radiator, water pump, etc
or air flow through the radiator, missing seals around the radiator mount, or seized fans
Or is could be that a sticking brake is making the engine work much harder all the time, which would also be the explanation for the fuel consumption.
Is the car otherwise standard?
Is it running the original airbox?
Is the air filter clean?
You need to replace the thermostat and then work out why the engine is overheating in the first place.
It might be a problem with the coolant flow; blocked radiator, water pump, etc
or air flow through the radiator, missing seals around the radiator mount, or seized fans
Or is could be that a sticking brake is making the engine work much harder all the time, which would also be the explanation for the fuel consumption.
Is the car otherwise standard?
Is it running the original airbox?
Is the air filter clean?
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Re: Low compression and high fuel consumption
Coolant flow - checkedwarpc0il wrote: ↑Sun Nov 15, 2020 1:23 pmI suspect that the thermostat was removed because the car had an overheating problem and someone thought that might fix, or at least mask, it. This was never going to work, for the reasons Chris says above.
You need to replace the thermostat and then work out why the engine is overheating in the first place.
It might be a problem with the coolant flow; blocked radiator, water pump, etc
or air flow through the radiator, missing seals around the radiator mount, or seized fans
Or is could be that a sticking brake is making the engine work much harder all the time, which would also be the explanation for the fuel consumption.
Is the car otherwise standard?
Is it running the original airbox?
Is the air filter clean?
Radiator - checked and cleaned
Water pump - checked
Fans - checked and replaced with series 2 fans
Airbox - original
Airfilter - replaced
Missing seals around the radiator // will double check this one
Sticking brake // need to check
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Re: Low compression and high fuel consumption
Maybe it’s a head gasket
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- 30405 (Sun Nov 15, 2020 11:42 pm)
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Re: Low compression and high fuel consumption
if it's the head gasket what can I expect? Any signs to identify if it's the head gasket?
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Re: Low compression and high fuel consumption
(There isn't a head gasket - that was a joke)
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Re: Low compression and high fuel consumption
Sorry that was a cheap joke, but I can understand how someone not familiar with the car may not understand it as such, I retract my statement
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Re: Low compression and high fuel consumption
That's ok mate. This is my 1st car and I've just bought it last month. I'm still a rookie for this mechanical stuff (especially for rotary) and I'm already suffering from this car. Help me to troubleshoot
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Re: Low compression and high fuel consumption
I get about that mpg when doing really short journeys.
I must say its a bit of a difficult first car this. Youll have some fun.
The only way to find out if its got low compression is to get it tested. There are so many things that can cause the symptoms you are experiencing that its important to rule them out.
If its over heating you want to take a look at this in line with the ignition components. Before you start spending money. take the plugs out and make sure everything is pushed together ok. take a note of what the coils are and pop a picture up here.
Is it using coolant? when you say its running how what exactally is happening? is it straight away. Does it happen if its kept below 5k but for a long period of time? how long are the journeys your taking?
I must say its a bit of a difficult first car this. Youll have some fun.
The only way to find out if its got low compression is to get it tested. There are so many things that can cause the symptoms you are experiencing that its important to rule them out.
If its over heating you want to take a look at this in line with the ignition components. Before you start spending money. take the plugs out and make sure everything is pushed together ok. take a note of what the coils are and pop a picture up here.
Is it using coolant? when you say its running how what exactally is happening? is it straight away. Does it happen if its kept below 5k but for a long period of time? how long are the journeys your taking?
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Re: Low compression and high fuel consumption
What do you mean by is it using coolant? Doesn't overheat below 5k. My longest journey so far was 200km and it didn't overheat. When driving normal it doesn't overheat. but when keep pushing hard like in the racing mode it quickly overheats within 1-2 kilometres.
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Re: Low compression and high fuel consumption
Using coolant means the level in the header / radiator tank will drop over time / miles
if this is true 1st check you have no weeping hose joints , signs of damp on the engine or under the engine
if you don't then its an internal issue with a failed seal
and please fit a thermostat
if this is true 1st check you have no weeping hose joints , signs of damp on the engine or under the engine
if you don't then its an internal issue with a failed seal
and please fit a thermostat
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Re: Low compression and high fuel consumption
Drove over 100km after refilling coolant and the coolant level didn't drop. So I'm guessing it's fine.350matt wrote: ↑Mon Nov 16, 2020 12:42 pmUsing coolant means the level in the header / radiator tank will drop over time / miles
if this is true 1st check you have no weeping hose joints , signs of damp on the engine or under the engine
if you don't then its an internal issue with a failed seal
and please fit a thermostat
Did you mean a seal inside the engine? can it be a reason for high fuel consumption? If so what should be the next step?
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Re: Low compression and high fuel consumption
If the coolant isn't dropping then great
next step is to fix the overheating
then worry about the fuel consumption
1st fit a thermostat
then do a compression test and possibly replace the plugs at the same time
let us know how you get on
next step is to fix the overheating
then worry about the fuel consumption
1st fit a thermostat
then do a compression test and possibly replace the plugs at the same time
let us know how you get on
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Re: Low compression and high fuel consumption
In Sri Lanka, we don't have a place that performs rotary compression tests. I've done 2 compression tests using analogue tester in 2 places and in the 1st one I got around 6 bar each rotor (cold engine) and the 2nd place I got 5 bars /70 psi each rotor (hot engine). So I'm guessing it must be something in between and the compression isn't good. Already replaced plugs and coils. I'm suffering from late starts as well. Sometimes it takes forever and sometimes it starts fine (still late).
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Re: Low compression and high fuel consumption
Check your spark plugs and also look at the underside of the ignition coils for cloudy spots on the insulation which is a sure sign of them breaking down.crteezy wrote: ↑Mon Nov 16, 2020 1:01 pmIn Sri Lanka, we don't have a place that performs rotary compression tests. I've done 2 compression tests using analogue tester in 2 places and in the 1st one I got around 6 bar each rotor (cold engine) and the 2nd place I got 5 bars /70 psi each rotor (hot engine). So I'm guessing it must be something in between and the compression isn't good. Already replaced plugs and coils. I'm suffering from late starts as well. Sometimes it takes forever and sometimes it starts fine (still late).
DO NOT buy from unknown traders on eBay even if the low price is inviting. Being in Colombo it is going to be expensive for you to buy coils and plugs and have them sent out to you from the UK but its the only way you will guarantee receiving quality parts.
Ryan Rotary Performance, Essex Rotary, Racing Beat Europe, Rotary Revs and the Performance Shop can all be trusted (plus others of course)
5bar is certainly an acceptable compression result so unlikely to be causing the the starting issue but only a rotary tester will show up each faces compression.
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Re: Low compression and high fuel consumption
Checked Plugs and Coils and they are fine. So does it mean a 5 bar compression doesn't cause a late start issue? I'm gonna check my battery tomorrow morning. If the battery also good what should I check next? Starter motor?
Last edited by crteezy on Mon Nov 16, 2020 5:02 pm, edited 1 time in total.
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Re: Low compression and high fuel consumption
How did you check the coils?
Rotary History;
Sep 2005-Aug 2006 EO55 XOL VR 231 New
Oct 2014-Mar 2019 OE06 EWJ VR 231
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Avatar courtesy of my grandson Cameron
Sep 2005-Aug 2006 EO55 XOL VR 231 New
Oct 2014-Mar 2019 OE06 EWJ VR 231
Jan 2019-Jun 2020 T200 CAD Orange SC 231
Feb 2020-May 2023 RR54 AJR VR 231 Modified for Track
Oct 2020-Mar 2021 YA56 EUE Copper Red Nemesis
Jun 2022-Apr 2023 TN07 JHD KURO Resurrected
Jun 2023-Jan2024 OV09 BFF Sparkling Black R3
Avatar courtesy of my grandson Cameron