MACS Monthly Newsletter - 2017 - APR1

Total Vehicle Climate and Thermal ManagementTM

April 2017

By Paul Weissler - MACS Senior Correspondent

UH OH! YOU BROKE SOMETHING
if you suffer a clumsy day and damage a turbo, you can't just
mount a new turbo assembly. In the case of the GM turbos, and
likely other makes, there are service parts kits for the bypass
valve, wastegate solenoid and wastegate actuator. See FIG. 1.
It's not a good day even to have to spring for any of those items,
but it sure beats a new turbo assembly-what you get might be
a stripped assembly anyway, with those parts listed for changeover. Yes, you have to be more careful working under the hood
today, but at least alternatives exist. ■

sandyblogs.com

Ugly happens in many ways when you're working on a car,
and although you learn to accept some of the damage, it hurts
both your work schedule and your bottom line. The situation
with today's more complex vehicles raises a lot of "what do I do
now?" questions.
Underhood is a real challenge. Components are "layered"
into place, so you often face the challenge of removing several
parts before you can reach the HVAC or cooling system ones
that you have to service or replace. More and more cars and light
trucks are turbocharged, and the trend is solidly in that direction.
Turbos provide power boosts on smaller-displacement engines
without noticeable effects on fuel economy, because most of the
boost occurs outside the range of EPA economy testing.
But a turbo is not just a single assembly. It includes lots of
hoses for air and coolant, and electro-mechanical parts, including solenoids. So you have to be really careful. A recent General
Motors study showed that technicians often cause damage to
them, and then face the problem of "restoration."
General Motors has been warning about the 1.6-liter turbo in
the 2016 Buick Cascada convertible, which seem to have been
coming back from dealers with damage to the solenoid vacuum
port fitting on the wastegate actuator and the bypass valve port
fittings. A friend of ours who has worked in the GM warranty
returns department tells us that when a less-than-scrupulous
dealer tech makes a mistake, he might do something additional
(and untoward) to a component to "create" a warranty failure.
An independent garage technician can't get away with that. So

Figure 1: It's important to be careful with removal and reinstallation of underhood and underdash parts from today's crowded areas, to avoid costly breakage.
This underhood 1.6-liter GM turbo is an example. Fortunately, among the often
broken parts are the solenoid port fittings on the wastegate actuators (labeled
A) and the bypass valve port fittings (B). Fortunately, there are service parts
kits for the bypass valve, wastegate solenoid and wastegate actuator, to keep the
damage within reason.

ALSO INSIDE THIS ISSUE:
Yes, turbos are new centers of attention......................................................................................................................... 2
Evaporator failures-the hvac case "shortcuts" ............................................................................................................ 2
And now for an evaporator leak we'd like to talk about................................................................................................. 3
What? Another General Motors anti-freeze .................................................................................................................... 3
Other antifreezes ............................................................................................................................................................... 4
We're sounding like a "broken record" ........................................................................................................................... 5
The new denso compressors - discussion by popular request ................................................................................... 7
Oil separator....................................................................................................................................................................... 8
Refrigerant blows open the pressure relief valve........................................................................................................... 8
MACS Service Reports is the official technical publication of the Mobile Air Conditioning Society Worldwide, Inc., P.O. Box 88, Lansdale, PA 19446. The material published in MACS Service Reports expresses the views of the contributors
and not necessarily that of MACS. Every attempt has been made to ensure

April 2017

the accuracy of the content of MACS Service Reports. MACS, however, will
not be responsible for the accuracy of the information published nor will MACS
Worldwide be liable in any way for injury, labor, parts or other expenses resulting
from the use of information appearing in MACS Service Reports.

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Table of Contents for the Digital Edition of MACS Monthly Newsletter - 2017