MazdaRx7Power

ok my car keeps jerking. today driving to work this morning going like 80 car jerked once and then it stopped, anyone know what that problem is???

another problem is i keep losing coolant. i know i have more water then coolant right now, but is it possible that the thermostat gets stuck at certain times and some of the water boils??? if it was the water seals there would be water in the oil or it would smoke alot at startup right????

i'm thinking of changing the coolant and spark plugs today.. anyone have any suggestions?

MazdaRx7Power

also when i let the car cool alot of air is in there thats why i was asking if you guys think the thermostat is getting stuck and burning the water?

zyounker

Sounds like coolant seals.. Good way to test this is buy buying these paper strips they sell that can test for exhaust gasses in coolant.. Cant think of what they are called right now.

You should also try replacing your radiator cap.. or have it tested..


-Zach

MazdaRx7Power

well would it smoke alot when first started if it was the coolant seals....

zyounker

um, it does sometimes. That is a symtom.. but i have had cars that did not to that and had a bad coolant seal..


-Zach

MazdaRx7Power

i am gonna try and get it pressure tested today hopefully comes out ok.... if not hey what can i do but rebuild...

zyounker

The strips would probably be easyer.. Should be able to get them at any auto parts store..

All they are is peices of paper that turn color if their is exhaust gas in your coolant. The car has to have just been run to test this though... If there is exhaust gas you will need a rebuild.

If you get it pressure tested and it is loosing pressure that does not mean the engine is bad.

-Zach

MazdaRx7Power

i'm gonna get those strips today?? can i get them at discount auto parts?? also will that block welder thing work as a temp fix to the problem for about 4 months if it is my seals. i have $700 saved up and need like 2 more months to be able to afford a rebuild.

zyounker

Well, No I think you are thinking of an oil leak by the dowel pins.. You can not fix the coolant seals without rebuilding the engine. And most likly it is because a previous owner did not change the coolant regularly and it ate the aluminum housings.

You should be able to get them at almost any auto parts store.. If not call your local radiator shop, they should have some.

-Zach

MazdaRx7Power

well i was reading this thread that said i could use a stop leak thing. put a link of it so u could see.

https://www.rx7club.com/forum/showth...ight=old+truck

zyounker

Yeah, i would not use any stop leak until you are sure it is the coolant seals.. But that is one thing that might prolong engine life..

-Zach

MazdaRx7Power

yeah i'm not gonna do that till i use those strips, if it comes out positive i have no choice but to do it. i cant afford rebuild right now.. but if the strips show that its not them then i'm gonna gut the thermostat change the plugs and change the coolant..

zyounker

Also check your radiator cap.. that is probably the leading cause of coolant lose..


-Zach

MazdaRx7Power

cap is less then 6 months old. i'll check all this out soon as i get home.

MazdaRx7Power

also why would the car jerk. yesterday leaving work it happened. started to accerelate and it started to jerk then all of a sudden took off. today driving to work it did it going about 80, then it stopped. anyone have a clue.

evel333

Use Block Weld, Alumiseal, etc. only as a last resort or if you just need to keep the engine running for "just a little longer"

BandAid fix--yes, but it may also reduce the efficiency of your heater core and water pump if too much deposits collect. Happened to me. It temporarily solved the problem and allowed me to run a few months more before the inevitable rebuild, but my heater has never been the same...

zyounker

Doubt the jerking is related.. What year FC is it? was it around 3K rpms?

Thing i could think of:
Bad fuel filter
Bad MAF sensor
Bad Wiring (Ground most likely)
Maybe bad injector.



Are you getting any error beeps when you turn on the ignition?

-Zach

MazdaRx7Power

87na. nope no beeps it just all of a sudden jerks. it did it while taking off and it did it today going about 80mph. fuel filter was changed in june, the MAF has the adapter i checked the little flapper it works fine. bad injectors wouldnt the car jerk all the time if the injectors were messed up.

zyounker

Well, The MAF can go bad without the flapper getting stuck.. but it should give you an error code..

The injectors can be intermitint.. So that is still a possibility..

Does it seem to happen when you are low on gas? maybe you have crap in the bottom of your tank?


-Zach

MazdaRx7Power

i have a half tank. but i'm just gonna change the plugs and hollow the thermostat that way its not getting stuck. and if that doesnt work then i'm gonna try the sealer.

zyounker

No, Don't hollow your thermostat!!!! BAD IDEA!!!!

You can't do that to mazdas. they will overheat..

Just get a new one. they are only ~$4..

-Zach

MazdaRx7Power

well its just a temp fix till i got the mazda one cause right now its a discount auto parts one. if you read my post from earlier someone did it to theres... had no problems...

https://www.rx7club.com/forum/showth...threadid=69719