[Joshyboy26]

Hey guys

Sierra swb with a 20v 4age.
It also has a tailgate mounted rad and fans.

Drove it to work for the first time today mixture of 80-100 and 60 kay zones for over an hour and my water temp never went over 60 degrees.
I wasnt thrashing it but wasnt grandma ing it either.

It has about 10l of coolant in the system and a fairly large rad.

Would this hurt the motor?
Should i be looking at a different thermostat?

I stopped at work and could still touch the rad so the gauge shouldnt bee too far out

[Jezza86]

Id put a restrictor card infront of the radiator. Its a sheet with a diamond cut out that limits the airflow through the radiator.
Then you can take the card out and resize the diamond to suit driving conditions

[bangn]

change the thermostat. ive had a few of these motors and they usually run a bit under half in the corollas. The genuine thermostats stick open when they fail so it could be tell tail signs of it opening earlier. Maybe also go for an aftermarket one as most of the time the flow is slower on them.

[Jezza86]

does that go for the thurmostats on the old 4A motors too bangn?

[Marko_SJ]

I interpret bangn's post as about the 4A's

[Jezza86]

4a was SOHC carby
4Age was DOHC 16 and 20 Valve

the change to a yamaha 16/20valve head where the thurmo is bolted to (atleast on the 4a it was) probably meant difrent thurmostats, which intrests me because i always though the old 4a in my ae82 didnt have a thurmostat.

[Marko_SJ]

Jezza86 wrote:

4a-c was SOHC carby
4Age was DOHC 16 and 20 Valve

the change to a yamaha 16/20valve head where the thurmo is bolted to (atleast on the 4a it was) probably meant difrent thurmostats, which intrests me because i always though the old 4a in my ae82 didnt have a thurmostat.

Never owned a 4A-GE, closest I've come is driving around a 4A-FE, which I rate as quite a good little engine, so can only imagine what a delight a 4A-GE must be.

You arent the only one to say this, about the early models at least apearing to not have a thermostat. Did it take forever to warm up from cold?

Maybe you'll find RollaClub or AE86DC interesting

http://www.ae86drivingclub.com.au/forum ... tat-needed

[bangn]

all 4A engines have a thermostat, if it doesn't its probably because the radiator is fucked and it keeps cooking.

the thermostats are different across the 4A engines, even on the silvertop and blacktop 20v's

Blacktop Thermostat: 90916-03075
Silvertop Thermostat: 90916-03060

4ac was carby sohc
4af-carby twincam but only ran a single cam gear
4afe EFI twincam - single cam gear

4age twincam 16v came in bigport and smallport versions both in NA and supercharged
4age twincam 20v in silvertop and blacktop

but yeh generally the thermostats stick open if they are genuine toyota ones.

20v has the thermostat attached to the side of the cyl head.. from memory the 16v 4age has a cross over pipe and thermostat on the GB normally.

20v's much more suited to a sierra id say, the 16V valley isnt sealed very well and would be prone to filling up with water if you visit water frequently. 20v will run water off the top
what box did you run?

[droverdave]

Where are you measuring the temperature?

[dank]

Yeah drover dave is onto it. If you measure the temp at the outlet of the head which is the angled pipe on the passenger side of the block it used to run around 85 deg which is the normal operating temp.

[bangn]

those motors take a fucking long time to bleed the cooling system too.. They take quite a while to get up to temp.

[Joshyboy26]

Ive got the sensor at the out let of the block.

Went 4wding on Saturday and it would hit 85 every so often id turn on the fans for half a minute and then it was back down to 75 again. I put some cardboard in front of it on sundayfor road driving and it made it better but still only 65 or so. It must get a fair bit of cooling off the pipes under the car.

Ive got a 3sp aisin warner a40 traumatic. Its a very similar setup to what dank used to run haha.
What did yours used to sit on dank? Ive got a different motor in it so maybe the thermostat is different?

[droverdave]

Do you have the sensor in the same position as OEM? Are you using an external thermostat housing off a FWD 4age? or a RWD engine setup.

You just have to make sure that your sensor is on the "inner loop" of the coolant path. IE the loop of coolant that goes around the engine before the thermostat opens up.

In theory the whole coolant system should end up the same temperature (by the thermostat), but in your case with such long pipes and the radiator so far away (and much better cooling effect of the radiator and pipes out in the open, I reckon you will experience much higher temperature fluctuations.

[Joshyboy26]

I think the housing is off a fwd. But the sensor is at what i am led to believe is the coolant out let from the block. I have a spare gauge and sendor perhaps i should put one on the other inlet and see what it is doing. Im on not sure where the original sendor goes. I think it might be on the other side but i could be wrong. The thermostat housing has been modified due to firewall clearance.

[droverdave]

Deleted, as information was incorrect.

[dank]

Mine used to sit on 85 no worries I had the thermos kick in around 95 from memory.

[Joshyboy26]

Mine is a 20 valve silvertop. I will put the thermostat out of your motor into it then dank and see how it goes.

[bangn]

they are normally on the thermostat housing with the fan switches. The 4A blocks have a fitting you can remove to wind a sensor into the block as well.

So it should be on the back of cyl 4 on the housing. (providing there is the room for it on a sierra)

[Joshyboy26]

Yeah thats where it is. On 20v s they apparently let the cold water into the motor unlike letting the hot out if you will.