here we go again. My 1992 DL-240 B230F is acting up. I drive for 15 mins and then TEMP rises just below RED space. I stop and turn on heater, TEMP falls back into NORMAL (9 am) space. This just started, car has 132,000 miles. My 4 plugs are white (0.30 gap), not good, idle is not right, motor jumping slightly, clicking sound also. Previous plugs showed "yellow" around tips????



I have done the following while problem above (some things below don't apply to finding fix):

(a) cleaned 2x rad and block, drained from block, very dirty, now has reg water. Don't want 50/50 installed until problem is fixed;
(b) new thermostat (87C/188F), nipple on thermo may be not at 10am or 2pm as VOLVO recommends for air relief;
(c) new clutch fan, could not tell if old one is broke, FCPeuro had sale;
(d) new NGK plugs at .030, BPR6ES;
(e) new pulley belts (very cracked after 10 years);
(f) new timing belt (timing is 12 deg BTDC, right on)
(g) new MAF (BOSCH)
(h) no coolant leaks, vacuum lines OK,

(i) 2 clusters indicate same high TEMP rise so compensator brd probably NOT the problem.;
(j) have I hurt the motor w/ high temp????



Any help appreciated. I plan on compression test today and coolant pressure test. I am thinking head gasket is going....what do you think??


Thx everyone...VOLVOs are the best!!

 

have you tested the impedance of the engine coolant temp sensor (cold and warm)?

A lean air mix can also cause cars to run hot - so I'd check for intake air leaks, clean the idle air valve etc.

does the fan come on when expected? any changes to the coolant level?

 

when you did the timing belt was the water pump changed out as well?
still think it is the temp comp board, mine does the exact same thing all the time and i know the engine is not overheating...sometimes the gauge will register nothing at all even though the engine is warm.

next time this happens you may not want to turn the heat on high and see what happens. i bet it will go to a different position on its own...