3200 Thermostat removal and replacement how to

cowsurgeon

Junior Member
Messages
354
So here goes.

The symptoms I had were of the engine running too cold most of the time. It would just reach 90 degrees on the gauge if I was sitting for long periods in stop-start traffic on a hot day. Driving anywhere normally, the temperature would drop to below 70 degrees, and at speed or in cold weather, would consistently run at just above 50 degrees.

As has been pointed out on here and on maserati forum, these engines ought to be run at the correct operating temps to avoid damage, so I thought I'd change the thermostat.

The thermostat itself is available from Eurospares for £102.90. The part number is 585045601. Adding VAT and postage this came to £130.25. Not a desperately cheap fix, so by doing it yourself at least you're saving the labour charge.

The coolant Maserati recommends is PARAFLU 11 (blue in colour and ethylene glycol based). This is available online from shop4parts:

http://www.shop4parts.co.uk/?name=store&op=Details&ProdID=79&sku=860

or from your local Alfa dealership - where I got mine. It costs around £6 a litre for concentrate, and should be mixed 50/50 with water.

27.jpg



Here's the how to:

Step 1: Unclip the air temperature sensor connector. You need to lift one edge of the small metal spring clip to do this. Don't let it ping off into oblivion...
1.jpg


Here's the connector removed:
2.jpg


Step 2: Undo clamp fastening air inlet sleeve to throttle body:
3.jpg


Step 3: Undo clamp fastening right air inlet sleeve to metal pipe:
4.jpg


Step 4: Undo clamp fastening left air inlet sleeve to metal pipe:
5.jpg


Step 5: With some wiggling remove the air inlet pipes:
Pipes removed:
6.jpg


and front of engine bay without them (you can now see the thermostat clearly):
7.jpg


Step 6: Waste 10 mins constructing a clever but utterly useless bit of kit to catch the coolant fluid:
9.jpg


Step 7: Undo clamp from coolant pipe to engine, beneath the throttle body:
10.jpg


Step 8: Realise futility of device made in step 6, resort to tried and tested method:
8.jpg


Step 9: Drain coolant from the pipe and thermostat itself by bending the pipe towards the ground into a collector:
11.jpg


Step 10: Undo the clamp connecting the same pipe to the thermostat itself:
12.jpg


Pipe removed:
13.jpg


Step 11: Drain further coolant from the thermostat:
14.jpg


Step 12: Undo clamp on pipe between thermostat and radiator:
15.jpg


Step 13: Undo 2 clamps on remaining small pipe between thermostat and engine, then wiggle thermostat until it comes off:
16.jpg



17.jpg


Front of engine bay without thermostat:
18.jpg


You should by now have collected about 4 litres of coolant, two sections of pipe and a knackered thermostat:
19.jpg



20.jpg


Step 14: Open box from Eurospares and compare old with new.
22.jpg



23.jpg


My old thermostat was jammed open - you can see daylight through it - the new one is closed as you'd expect:

Old:
21.jpg



New:
24.jpg


Step 15: Reconnect the small rubber pipe to the thermostat at the correct angle:
25.jpg


Step 16: Reconnect thermostat to hoses. Push them all on as far as they will go and tighten all the clamps well. Reconnect the air inlet pipes, making sure they are also pushed well onto their fixings before tightening the clamps. Don't forget to reconnect the air temperature sensor connector.

Engine bay all back together:
26.jpg


Step 17: Refill the coolant system with coolant and water in 50:50 mix as follows (my sincere thanks to Nigelo for the instructions):
28.jpg


Hi Chris

I don't believe there are bleed nipples on the 3200, certainly none that I know of, since the configuration has no dead drops unlike most mid-engined chariots.

Refill procedure is straight forward - Take your time, don't rush and under no circumstance be tempted to fill above the max mark on the header tank at any time. You will usually find the coolant disappears from the header tank quite quickly. When you are satisfied you have reached the limit, refit header tank cap, turn heater temp to max, start engine and let it idle for a few minutes but don't allow it to reach normal temp. Stop engine, carefully release cap and fill to max mark. Depending on how much more coolant it has taken, repeat if necessary. Finally bring up to normal temp and perform visual level check only but do NOT release cap. If it needs more coolant, allow engine to cool first. Take it for a short drive, allow to cool and recheck level. Recheck level at increasing intervals until you are confident it has stabilised. To repeat, NEVER refill above max mark

It goes without saying, that you should check for leaks after refilling and again after the engine is up to temp.

Good luck

Nigel

Mine took 3 litres of coolant/water mix (ie: 1.5 litres of each), before it was up to the MAX level. Two 3 min runs of the engine idling, and there was no change in the level. I then ran the engine for around 10 mins, up to correct temp, and until the radiator fans came on. It had then dropped to the MIN level. So I'm letting it cool before refilling as per Nigelo's instructions.

Engine temp came straight up to just below 90 degrees within a couple of minutes of starting her up - all sorted!!:
29.jpg


Hope this helps!!!
 
Last edited:

Parisien

Moderator
Messages
34,927
Truly excellent Cowsurgeon.........a Haynes manual is so 3rd division compared to your high quality, thorough and professional version!

P
 
Last edited:

Spike62

Junior Member
Messages
253
Can not wait to have a go myself now, feel brave enough to tackle the job with these excellent photos and instructions. Well done from me !!
 

conaero

Forum Owner
Messages
34,593
Brilliant, brilliant, brilliant, Chris, welcome to the DIY Technical Guide club!
 

rs48635

Member
Messages
3,181
Top work.
Just a thought on that electrical connector, worked on a few italian cars, breaking the odd clip like this. Usually connector clip can be released by pressing the middle of the metal bar, which releases the side clips allowing connector to slide off.
 

Spike62

Junior Member
Messages
253
Finally got around to tackling this job now it's winter and it took me 45 mins due to these excellent instructions. Thanks again. Temp now bang on 90
 

GDL

Junior Member
Messages
147
It may be a daft question but.....

Is there no way to get the housing open and replace the thermostat itself?
I know its a Maserati and things are expensive but a thermostat shouldn't be more than a fiver and £108 +vat + postage seems a **** of a lot

Cheers

Gordon
 

lozcb

Member
Messages
12,301
It may be a daft question but.....

Is there no way to get the housing open and replace the thermostat itself?
I know its a Maserati and things are expensive but a thermostat shouldn't be more than a fiver and £108 +vat + postage seems a **** of a lot

Cheers

Gordon

Looks to be a sealed unit , looks pretty easy to open up and probably easy to obtain an equiverlant thermostat Possibly Alfa part , the hard part will be getting a water tight seal that will cope with the pressures required , cold dark nights and on the phone to the AA spring to mind , worth a try but its only a £100


regards loz
 

GDL

Junior Member
Messages
147
Any of you chaps that have recently or about to replace fancy donating your unit for a little experimentation?
 

dem maser

Moderator
Messages
34,221
it only reaches 90 when its been on for 20 mins..is that normal??

i read on here that it reaches 90 in 2 mins that sounds wrong to me...
 

Spike62

Junior Member
Messages
253
The housing is one moulded unit, changed the thermostat on my sons Fiesta the same week, total cost £8.70 inc VAT, the 3200, little change from £130 once 2 ltrs of anti-freeze purchased as well.

Mine reaches 90 in a few mins now and I've done over a 100 miles this week and its not moved and my heater works at last......success!
 
Last edited:

RSM Masser

Member
Messages
2,437
The housing is one moulded unit, changed the thermostat on my sons Fiesta the same week, total cost £8.70 inc VAT, the 3200, little change from £130 once 2 ltrs of anti-freeze purchased as well.

Mine reaches 90 in a few mins now and I've done over a 100 miles this week and its not moved and my heater works at last......success!

My daughters 10 year old Astra - thermostat £45 + vat, New Mondeo £120, Maserati 3200 £102 - bargain!
 

NickP

Member
Messages
1,623
Excuse my ignorance here - but is this thermostat the same as an engine temperature sensor?

No, the thermostat controls the flow of water between the engine and cooling system, it opens up when the water inside engine has reached a certain temperature. The temperature sensor is an electronic thermometer. I think...
 

Sniffer

New Member
Messages
37
I think the thermostat is the same as that fitted to an Alfa 155 1993-1995 - Equiv is a QH QTH551K. Probably out of the same factory!. QH part is around £70.
 

RSM Masser

Member
Messages
2,437
Very similar looking I agree - but probably a major differnce in pipe size or somthing that will make it useless