What Causes High EGT on a 6.7 Cummins & How to Fix It

High exhaust gas temperatures (EGTs) can be a silent killer for your 6.7L Cummins engine. Whether you're towing heavy, daily driving, or running performance mods, keeping your EGTs in check is critical for engine longevity and power.

In this post, we’ll break down:

Normal EGTs for a 6.7 Cummins

Tip: Anything over 1250°F for too long can lead to serious engine or turbo damage.

What Causes High EGT on a 6.7 Cummins?

Here are the most common culprits:

1. Turbo Too Small or Too Slow

A restrictive or undersized turbo can’t push enough air at higher RPMs, especially under load. The result? Hotter combustion = high EGT.

Fix: Upgrade to a high-flow turbo like the DPS S467.7 VGT for better air volume and faster spool.

2. Overfueling

Bigger injectors or aggressive tuning without the airflow to match will spike your EGTs fast.

Fix: Match your fuel mods with the right airflow (turbo + manifold), and get a custom tune.

3. Plugged or Restrictive Exhaust

A clogged DPF, narrow downpipe, or crushed exhaust system traps heat.

Fix: Upgrade to a high-flow exhaust or consider a performance manifold like the DPS 2-Piece 6.7L T4i Manifold to reduce backpressure.

4. Excessive Load

Heavy towing in high gears at low RPM = not enough boost = high EGTs.

Fix: Downshift sooner, and monitor boost with a gauge. Consider compound turbos for towing-heavy builds.

5. Bad Intercooler or Boost Leaks

Leaks in your intercooler system or a failing charge-air cooler reduce air density.

Fix: Pressure test your intercooler system and replace worn boots or clamps.

How to Lower EGT on a 6.7 Cummins

Here’s a quick checklist of effective solutions:

✅ Turbo Upgrade

• A larger or variable-geometry turbo (like the DPS Turbonator VGT) increases flow and lowers EGTs by 150–300°F.

✅ Free-Flowing Exhaust Manifold

• A high-silicon ductile iron manifold prevents heat soak and reduces thermal stress.

✅ Compound Turbo Kit

• Adds a second turbo to multiply airflow, ideal for towing or 500+ HP builds.

✅ Tuning Adjustments

• Dial back fueling or optimize timing via EFI Live or MM3.

✅ EGT Gauge

• Monitor temps in real time. Place the probe pre-turbo for accuracy.

Recommended Products

Compound Turbo Kit for 6.7 Cummins

Turbonator® VGT Ball Bearing Turbo

DPS 6.7L T4i Exhaust Manifold

All of these are designed to increase airflow, lower EGTs, and improve reliability, especially when towing or tuned.

FAQ

Q: Will high EGTs damage my turbo?
A: Yes. Sustained temps above 1300°F can crack housings and damage turbine blades.

Q: How can I monitor EGT on a stock truck?
A: Install a pyrometer gauge with a pre-turbo probe for best accuracy.

Q: Do compound turbos always lower EGT?
A: Yes, if sized correctly. They multiply airflow and reduce strain on the primary turbo.

Ready to Lower Your EGTs?

Don't wait until your turbo fails. Upgrade your airflow and keep your Cummins cool under pressure.

Call us at 801-930-8404 or

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