View Full Version : clogged radiator?????

1st time cadddy
04-07-08, 12:00 AM
1998 deville n* 109k
bought this car for my son 3 mos ago.
he used it twice and it heated up on him, so he decided he wasn't going to use it, and thought it be best that he use my 07 yukon
finally had a chance and good weather to look at it today (n.e. pa)

first checked colant level took 1 gal 50/50 dex
let idle for over 1 hr. temp made it up to 222 then down to 199 (fans came on at 220)
felt around hoses and rad all seemed to be even heat.
shut it down and cooled, checked coolant level, took another qt.
started it again this time noticed small amount of steady white smoke out tail pipe, outside temp was 42, attributed it to condensation.

took for long local drive (15 mi.) got up to 205 and dropped to 185.
decided to try it on the highway.
got on it a bit and temp come right up to 255.
started down long hill (5mi, 4 1/2 % grade) dropped down to 170
decided to try and climb back up, bad move, climbed to 245 and held steady to top then overheated.

while sitting there on the side of the road feeling stupid, (no phone, coffee, or cigerettes.) i felt that the radiator was ice cold, further the lower rad hose was warm but no where near 275, the t stat housing was red hot but the hose was not nearly as hot.

after cooling i drove back home at low speed, stopped for a new t stat.
flushed system and replaced t stat.

now it seems to be running steady around 200, locally, too scared to take it back on the highway.

sound like a clogged radiator????

04-07-08, 04:55 AM
Have you drained the coolant (intentionally)? If it looks crappy you may have a clogged radiator, but that tends to be a less common issue judging from post histories. You did the t-stat already, I would check the water pump belt and tensioner, (driver's side end of front camshaft cover, under a black shield) R&R if necessary and head for the highway. Bring cell phone, smokes and mechanic lubricant, maybe pack a lunch.

04-07-08, 08:08 AM
Check 3/4" cross over coming off the thermo housing to the expansion tank as well. At cold idle pull the end going to the tank, you should see a flow, if not it's clogged, clear it if needed. 200 local is not a problem. My 96DeVille runs 207 +- local and high way. Small spikes are not necessarily a problem - unaccounted for loss of coolant is. What your seeing could be air lock. Have you felt the heater hoses going through the fire wall, both should be hot. Do like chubby says and be sure to bring your ciggies. K_C

04-07-08, 10:25 AM
I don't like the sound of continually having to add coolant.