Parts Catalog Accessories Catalog Tech Info Tech Forums
 
Follow Pelican Parts on Facebook Follow Pelican Parts on Twitter Follow Pelican Parts on Instagram Follow Pelican Parts on YouTube Follow Pelican Parts on Pinterest Follow Pelican Parts on Tumblr
  Search our site:    
View Recent Cars  |   Cart  | Project List | Order Status | Help    
 >  >
Cooling System Leak Test
 
Bookmark and Share

Pelican Technical Article:

Cooling System Leak Test

Nick Czerula

Time:

1.5 hours

Tab:

$20

Talent:

**

Tools:

Cooling system pressure tester

Applicable Models:

BMW E46 M3 Coupe/Conv (2001-06)
BMW Z4 Convertible (2003-08)
BMW Z4 Coupe (2006-08)

Parts Required:

Engine coolant. Additional parts will be determined once leak is found.

Hot Tip:

Check for leaks with engine warm and cold.

Performance Gain:

Repair coolant leaks

Complementary Modification:

Replace associated hoses and cooling system seals.

Pressure testing your BMW Z4 cooling system is the best way to find leaks. However, not everyone has a pressure tester. I would suggest owning one if you plan to maintain your own vehicles, it can save quite a bit of time when locating a cooling system leak. You can also check for leaks without a pressure tester, but results are less accurate and the procedure is time consuming. I will cover pressure testing in this tech article, as well as some tips on checking for leaks without using one. Always start with a cool engine, if you do not find the leak, warm the engine with the pressure tester installed. At times, leaks will surface as parts expand from engine heat.

A cooling system pressure tester is used to pressurize a cooling system and hold at a specified pressure while looking for leaks. Coolant leaks can be internal (ie: head gasket) or external (ie: radiator), it is important to take these things into consideration when looking for a coolant leak. If you are losing coolant, but not seeing any on the ground, this would likely be an internal coolant leak. Puddles of coolant found under your vehicle would be from an external leak. Remember to properly clean any coolant that gets on ground and properly dispose of it as it is toxic. Place a drain pan under suspected areas of leaks to minimize coolant spills.

BMW Z4 models can develop coolant leaks toward the front of the engine, in places like the radiator, water pump and thermostat. The rear or side can be the coolant reservoir, heater core and heater hoses. A pressure tester is the quickest way to find these leaks.

When pressure testing a cooling system, be sure the vehicle is cool and lacks pressure.
Figure 1

When pressure testing a cooling system, be sure the vehicle is cool and lacks pressure. Then, remove the coolant expansion tank cap. Once the cap is removed, install pressure tester adapter (inset) to the coolant expansion tank.

Pressurize system to 1.
Figure 2

Pressurize system to 1.5 bar (21.8 psi). Pressure should not drop more than 10% over a two minute time period. If pressure drops right off, that is a sign of a leak. Look for coolant on the ground. If no coolant reaches ground, you could have an internal leak. If you suspect head gasket leak, you need to test cylinder sealing via a leak down test. If coolant leaks externally, use a flashlight and follow coolant to source.

Coolant leaking down the left side of engine could be connecting pipe sealing O-rings (red arrow).
Figure 3

Coolant leaking down the left side of engine could be connecting pipe sealing O-rings (red arrow). This pipe runs along the cylinder head and is sealed with O-rings at the back of the thermostat and along the cylinder head. Look for coolant on the edges of the oil pan, left side if you suspect it is leaking. If needed, remove the engine hook (blue arrow) for a better view.

Coolant leaking down the right side of engine could be the radiator outlet temp sensor (red arrow), note the wet area around the sensor showing signs of a small leak.
Figure 4

Coolant leaking down the right side of engine could be the radiator outlet temp sensor (red arrow), note the wet area around the sensor showing signs of a small leak. Or possible leak along the side tank on the radiator (blue arrow). This vehicle was losing a small amount of coolant over time with no coolant reaching the ground. Right side radiator tank shown, the left can also leak.

Bookmark and Share

  Search our site:    

View Cart & CheckOut | Project List | Order Status |  Help    

 

[Home] [Customer Service] [Shopping Cart] [Privacy Statement]
 [Contact Us] [About Us] [Shipping] [Map to our Location] [Careers]

Copyright © Pelican Parts Inc.

Page last updated: Fri 12/9/2016 03:04:49 AM