Logo
FULL SITE MENU

Suzuki DF70 overheating issue — looking for specialist advice

B

BgibboRib

New member
Suzuki DF70 overheating issue — looking for specialist advice.

Engine starts and runs perfectly. Cooling telltale is strong initially, but after a few minutes running (especially around 3000+ rpm) the telltale drops down to a weak trickle and shortly afterwards I get an overheat alarm and the engine goes into protection/limp mode.

Work already done:

  • Complete water pump service: new impeller, key, wear plate and gaskets.
  • Checked pump housing, no obvious scoring/damage.
  • Both mechanical thermostats replaced.
  • Both temperature sensors replaced (head and exhaust side).
  • Exhaust side plate removed and inspected — no salt/blockage found.
  • Cooling passages flushed with hose/pressure washer/compressed air — flow appears good.
  • Telltale itself removed/cleared, no blockage.
  • Good water flow when flushing up the water tube with lower unit removed.
Interesting point: after stopping and letting water drain back, restart gives a strong telltale again temporarily, then the problem returns.

Question:
Has anyone seen a DF70 lose cooling flow after a few minutes like this? Could the pump be losing pressure under load, an exhaust manifold cooling issue, grommet/seal problem, or something else?

Any Suzuki mechanic experience appreciated — running out of things to check.
 
One year now i try to find the cause of this issue to a client of mine with a df70 2008 model. this engine had already other issues other than the temperature. we fixed the seat on one exhaust valve, and after that compression is good in all4 cylinders. But if you travel at 4000rpms and lower everything is fine, above 4k temperature alarm and safe mode. let it cool and then again the same. new water pump kit installed, new thermostat, new water relief valve, isuue still there. The alarm is from the exhaust manifold sensor which is really because i used a infrared thermometer and indeed the temperature rise to 105C when alarm hit. So after the last alarm i removed the exhaust manifold and found some water on the exhast side which souldnt have happened. So i suspect a leak between the exhaust side and coolind passage side. i am expeecting the exhaust to come back from the welding workshop to see.
 
Back
Top