MACS Monthly Newsletter - 2017 - APR2

YES, TURBOS ARE NEW CENTERS OF ATTENTION
The more hoods you raise on late-model vehicles, the
more likely you are to see a turbocharged engine. This
means that there's another heat exchanger at the front of
the engine for you to pay attention to when there's an
air conditioning-related airflow issue to diagnose. And
because most of the turbos are water-cooled, they're another source of possible leakage.
Ford has become the "turbo leader" among U.S.
brands, featuring its "Eco-Boost" label. Turbos help car
makers increase fuel economy because the engine itself
is of small displacement, so "it's performance when you
floor the pedal, but not when you're doing 'normal' driving and highway cruising," which is when most of the
tests measure emissions.
Charge air coolers that use ambient air for cooling are
primarily in large trucks; cars and small crossovers/
SUVs use water-cooled and have for many years (think
Subaru). The Ford Eco-Boost engines are a modern example, and they should be kept in mind for cooling system issues. Example: the 2014-on Ford Fusion with the
1.5-liter direct injection EcoBoost turbo (plus the 2017 Escape with the same engine), which occasionally has suffered from white smoke (certainly a coolant tipoff) and
low coolant level. The problem turns on the MIL and
logs five misfire codes, plus one or two overtemperature
codes (P0217-coolant, and P1299-cylinder head overtemperature active).
The basic check is a cooling system pressure test. If
the system doesn't hold pressure, you have to go through

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normal cooling system diagnostics. If it does hold pressure for at least two minutes, remove and inspect the
charge air cooler at the lower edge, where you'll likely
find contact with an intake manifold bolt that backed out
and damaged it (FIG 2). Ford recommends replacing the
manifold and the charge air cooler. If all you find is leakage from the CAC, replace that. Service details are in a
Ford bulletin, so once more we won't go into them, or list
all the part numbers. The point is that turbos and CACs
are now a major factor in cooling system service and even
A/C performance. ■

Figure 2: Damage to this lower edge area of the charge air cooler on 2014-17
Ford Fusions with the 1.5-liter EcoBoost turbo, that results in coolant leakage, likely was caused by a bolt backing out from the intake manifold. If this
happens, both intake manifold and charge air cooler must be replaced.

EVAPORATOR FAILURES-THE HVAC CASE "SHORTCUTS"
beam so you don't have to remove it. But there also have
been a few that involve cutting a bolt head instead of removing a bolt you can't reach with any known wrench
or alternative. Or the technician can get a particular bolt
out, but during the HVAC case installation, there is absolutely no way he can get it back in. Because the part
is held by other bolts, he is confident it won't loosen
(badly?) and create a problem. However, there's soon
an offensive rattle and he has to explain to the customer
that he saved him hours of labor charge and the rattle
should be no real issue. Well maybe. We have heard of
using that bolt with the cut-off head as a pilot, so at least
it functions as a guide into a mounting hole. We think
we've gone as far as we can with this. It comes down to
knowing the customer, and having a good "feel" for that
missing bolt. ■

Evaporator leaks are not only the toughest to positively
identify, but usually the toughest to repair, because of the
access issue. On most late-model cars there's a crossbody brace under the dashboard that makes it necessary
to remove the dashboard, and that often is a full-day job,
or even longer. So you want to make sure the problem
really is the evaporator. What can be even worse is when
the evaporator is "just" a half-day job-still not inconsequential-and the shop goes ahead with an R&R and discovers nothing wrong with the evaporator.-talk about a
reason for a grown man to cry.
Because so many evaporators are so difficult, there's a
"cottage industry" in shortcuts for an R&R. Almost every HVAC technician can tell you how he turned a particular 10-hour evaporator case R&R into a great time-saver
with his secret method.
Some of the shortcuts involve careful bending to clear a

April 2017

MACS Service Reports

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